An adult case of thrombocytopenia associated with posterior mediastinal hemangioma suggestive of Kasabach–Merritt phenomenon with uncertain diagnosis

Abstract

Mediastinal hemangiomas are rare, accounting for <0.5% of all mediastinal tumors. Kasabach–Merritt phenomenon, characterized by thrombocytopenia and platelet consumption associated with vascular tumors such as Kaposiform hemangioendothelioma and tufted angioma, is even rarer, especially in adults. Adult cases of Kasabach–Merritt phenomenon complicated by posterior mediastinal hemangioma are exceedingly uncommon and pose significant diagnostic challenges. This report describes the case of an adult with thrombocytopenia and posterior mediastinal hemangioma exhibiting features suggestive of Kasabach–Merritt phenomenon; however, a definitive diagnosis could not be established due to the absence of characteristic histological or molecular evidence of Kaposiform hemangioendothelioma or tufted angioma. The patient had been initially diagnosed with thrombocytopenia >10 years before admission, and during a routine physical examination, a posterior mediastinal mass was observed. The patient underwent successful surgical resection, and her platelet count normalized postoperatively; however, it remains uncertain whether this improvement was primarily due to the surgical removal of the lesion or perioperative transfusion support. Follow-up tests at 2, 4, and 8 weeks after discharge showed sustained normalization of platelet counts. This case highlights the diagnostic uncertainty in an adult patient suspected of having Kasabach–Merritt phenomenon and the treatment challenges involved in the management of mediastinal hemangiomas, underscoring the importance of diagnostic caution and clinical awareness necessary for distinguishing between conditions with similar presentations.

Introduction

Posterior mediastinal hemangiomas are rare benign or borderline tumors, accounting for <0.5% of all mediastinal tumors. ¹ They are often asymptomatic and usually identified incidentally during physical examinations. Imaging, particularly computed tomography (CT), does not reveal specific features, and preoperative diagnoses commonly suggest a posterior mediastinal mass or neurogenic tumor. Treatment options typically include conservative management or surgical resection, depending on the tumor size and symptoms.

Kasabach–Merritt Phenomenon (KMP) is a rare coagulopathy, predominantly affecting infants and young children. It is characterized by thrombocytopenia or consumption coagulopathy associated with Kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). ² Although KMP is typically treated with steroids and/or vincristine as first-line therapies, surgical resection of the hemangioma may be required in certain cases to control platelet consumption and improve coagulation status. ³ However, adult-onset KMP, particularly with posterior mediastinal hemangioma, is extremely rare, and no clinical guidelines currently exist to provide a clear management approach.

This report presented a case of a 53-year-old female patient exhibiting clinical findings suggestive of KMP, although a definitive diagnosis could not be established due to coexisting posterior mediastinal hemangioma. The patient presented with a posterior mediastinal mass identified during a routine physical examination. Following surgery, her platelet count normalized, and she was discharged on postoperative day 7 with a stable platelet count. This case report underscores the diagnostic uncertainty and therapeutic complexity associated with suspected adult-onset KMP and highlights the importance of cautious interpretation and individualized treatment planning in such rare presentations. The reporting of this case conforms to the Case Report (CARE) guidelines. ⁴

Case report

This case report was reviewed and approved by the Ethics Committee of Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School (Approval Number: 2024-683). Written informed consent was obtained from the patient for the publication of this case report and any accompanying images. The patient was informed that all identifying information would be kept confidential and removed from the published material prior to submission.

A 53-year-old woman underwent a routine physical examination 3 weeks prior to admission, during which CT revealed a posterior mediastinal mass. A contrast-enhanced CT of the chest performed 2 weeks before admission identified a soft tissue mass approximately 3.7 × 2.5 cm² in size, located in the right paravertebral region. The scan revealed heterogeneous enhancement with areas of progressive enhancement and patchy low-density regions. There was no evidence of enlarged lymph nodes in the mediastinum (Figure 1(a)). Upon admission, the patient’s medical history was reviewed, revealing no specific complaints related to the mass. Notably, the patient had undergone a hysterectomy for uterine fibroids 10 years earlier, during which thrombocytopenia was incidentally detected and left untreated. No other significant chronic medical conditions were reported.

Figure 1.

Preoperative and intraoperative imaging of a 53-year-old woman with a posterior mediastinal mass. (a) Contrast-enhanced computed tomography (CT) of the chest performed 2 weeks before admission showed a right paravertebral soft tissue mass (3.7 × 2.5 cm²) with heterogeneous enhancement and patchy low-density regions without mediastinal lymphadenopathy. (b) Noncontrast chest CT performed on the first hospital day demonstrated a posterior mediastinal mass adjacent to the right paraspinal region, with suspected cortical distortion of the right 3rd–5th ribs. (c) Thoracic magnetic resonance imaging (MRI) performed on the first hospital day revealed an oval-shaped lesion (3.5 × 2.6 cm²) at the level of the T6 vertebral body, showing heterogeneous long T1 and long T2 signal intensities, suggestive of a neurogenic tumor and (d) intraoperative thoracoscopic view of the paraspinal mass, which was encapsulated, highly vascular, and later diagnosed as a hemangioma.

Upon admission, in addition to platelet count, essential laboratory tests were conducted to support the diagnosis of KMP. The patient’s fibrinogen level was markedly reduced to 1.5 g/L (normal range, 2–4 g/L), indicative of consumptive coagulopathy. D-dimer level was elevated to 6.8 µg/mL (normal range, <0.5 µg/mL), which further supported the presence of active coagulation and fibrinolysis. Additionally, prothrombin time (PT) and activated partial thromboplastin time (APTT) were abnormal, with PT prolongation to 14.5 s (normal range, 11–14 s) and APTT of 40 s (normal range, 25–35 s), suggesting coagulopathy typical of KMP. Lactate dehydrogenase (LDH) level was markedly elevated to 950 U/L (normal range, 120–240 U/L), consistent with microangiopathic hemolytic anemia, which was also suspected given the presence of fragmented red blood cells on peripheral blood smear. Further testing confirmed the diagnosis of microangiopathic hemolytic anemia, with a peripheral smear showing schistocytes and reticulocytosis. These findings, in combination with thrombocytopenia and low fibrinogen and elevated D-dimer levels, were suggestive of KMP in the context of a vascular tumor, particularly hemangioma. However, a definitive diagnosis could not be established due to the lack of pathological confirmation of KHE or TA. On the first hospital day, a repeat plain CT revealed a mass in the right posterior mediastinum adjacent to the paraspinal region, suspected to be a neurogenic tumor, with a cortical distortion of the right 3rd to 5th anterior ribs (Figure 1(b)). Considering that the mediastinal mass was close to the paraspinal region, plain thoracic magnetic resonance imaging (MRI) was performed. The scan revealed an oval-shaped lesion with long T1 and T2 signals at the level of the T6 vertebral body on the right side. The signal intensity was heterogeneous, and the lesion measured approximately 3.5 × 2.6 cm², which was interpreted as a neurogenic tumor (Figure 1(c)). One day after admission, a routine blood test revealed a platelet count of 17 × 10⁹/L (normal range, 100–300 × 10⁹/L) (Table 1). Based on the low platelet count, the patient was administered 20 mg of Leekejun and 2 therapeutic doses of irradiated apheresis platelets. A follow-up blood test after platelet support therapy showed an increased platelet count of 82 × 10⁹/L (Table 1), prompting continued platelet support. On the day prior to surgery, her platelet count was 152 × 10⁹/L (Table 1), which was within the normal range.

Table 1.

Patient’s recordable platelet count, which was below the normal range before surgery and normal after surgery.

Time	Platelet count (×109/L)
Before hospitalization	<50
3 days before surgery	17
2 days before surgery	82
1 day before surgery	152
1 day after surgery	127
3 days after surgery	151
5 days after surgery	144
6 days after surgery	141
2 weeks after discharge	147
4 weeks after discharge	152
8 weeks after discharge	156

To further investigate the cause of thrombocytopenia and ensure a comprehensive diagnosis, additional evaluations were performed. A bone marrow biopsy was conducted on hospital day 3 to assess platelet production, given the patient’s long-standing thrombocytopenia. The bone marrow aspirate showed adequate megakaryocytes, indicating that the thrombocytopenia was not due to impaired platelet production but was more likely consumptive in nature. Additionally, screening for antiplatelet antibodies was performed, and the results were negative, ruling out immune-mediated thrombocytopenia. The patient’s medication history was reviewed, which revealed no use of drugs known to affect platelet count, such as antiplatelet drugs or anticoagulants, thereby excluding drug-induced thrombocytopenia. Infection screening, including cultures and polymerase chain reaction (PCR) tests, was performed, which was negative for any active infections. Additionally, autoimmune disease workup, including tests for autoantibodies, such as antinuclear antibodies (ANA), anti-dsDNA, and antiphospholipid antibodies, was also conducted. The test results were negative, thereby ruling out an autoimmune etiology for thrombocytopenia. To evaluate for splenomegaly, a common cause of thrombocytopenia, an abdominal ultrasound was performed, revealing a normal-sized spleen with no evidence of splenomegaly. A peripheral blood smear on admission revealed mild thrombocytopenia with no abnormal platelet morphology, and there was no evidence of hemolysis or fragmented red blood cells, which might suggest microangiopathic hemolytic anemia. Given the patient’s history of thrombocytopenia for over 10 years, it is likely that the condition was chronic and independent of the newly discovered hemangioma. This long-standing thrombocytopenia could be due to a primary platelet production abnormality or another underlying benign cause. However, the recent identification of the hemangioma, combined with the acute changes in the platelet count, raised concerns regarding a possible consumptive process, such as KMP, prompting the additional diagnostic workup described above.

After successful induction of general anesthesia, the patient was positioned with the left side up on the operating table. A 3-cm incision was made along the right fifth intercostal anterior axillary line, extending to the midaxillary line. The incision was deepened layer by layer to access the chest cavity. A thoracoscopic probe was inserted, revealing adhesion in the chest cavity. Exploration identified a right paraspinal mass with a thin capsule and rich blood supply, which was diagnosed as a hemangioma (Figure 1(d)). The mass was carefully excised, and prolene sutures were used to close its wide base, which was associated with significant bleeding. The chest cavity was irrigated, and following lung expansion, no active bleeding was detected. Subsequently, a thoracic drainage tube was inserted, and the incision was closed in layers. The patient’s vital signs remained stable throughout the procedure. Intraoperatively, the patient received 3 units of red blood cells, 350 mL of plasma, and 2 therapeutic doses of irradiated platelets.

Upon surgical resection, the tumor was sent for histopathological evaluation. Microscopic examination revealed vascular spaces lined by endothelial cells; however, the tumor’s histological subtype could not be conclusively determined as hemangioma, KHE, or TA due to the absence of specific histologic features. For further tumor evaluation, immunohistochemical staining was performed, which yielded the following results.

Cluster of differentiation (CD) 31 (endothelial marker). Positive, supporting endothelial origin;

CD34 (endothelial marker). Positive, confirming a vascular tumor;

D2-40 (lymphatic marker). Negative, ruling out lymphatic tumor origin;

Keil 67 (Ki-67). Proliferation index of 15%, indicating moderate cellular proliferation but not high enough to suggest aggressive behavior such as KHE or TA;

Factor VIII-related antigen. Positive, further supporting vascular endothelial differentiation.

These markers provide stronger evidence in favor of the mass being a hemangioma. However, KHE or TA could not be completely excluded without further molecular analysis. Although the immunohistochemical profile (CD31, CD34, factor VIII positivity, D2-40 negativity, and Ki-67 index of 15%) supported a vascular endothelial origin consistent with a hemangioma, these findings could not completely rule out KHE or TA. Definitive distinction between hemangioma, KHE, and TA often requires molecular genetic analysis, particularly testing for phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and Harvey rat sarcoma viral oncogene homolog (HRAS) mutations. Further, the vascular nature of the tumor and association with KMP also warranted molecular genetic testing. However, such testing was not performed in this case due to local limitations, which represents a diagnostic constraint. If available, testing for PIK3CA mutations, commonly associated with KHE, or HRAS mutations in TA would have been informative. PIK3CA mutations have been identified in KHE, and their absence would further suggest a benign vascular tumor, such as a hemangioma, rather than a malignant or complicated form. Bone marrow examination was not performed; however, given the long-standing thrombocytopenia (>10 years), which was chronic and unrelated to the hemangioma, the assessment was regarded unnecessary at the time of admission. No significant splenomegaly or autoimmune signs were noted. A peripheral blood smear was reviewed, showing no signs of microangiopathic hemolytic anemia or abnormal platelet morphology, supporting a nonmalignant origin of the thrombocytopenia. Autoimmune disease workup was not indicated due to the absence of other clinical features suggestive of an autoimmune etiology for the thrombocytopenia. Given the lack of definitive histological evidence of KHE or TA, the diagnosis of true KMP could not be established. Therefore, this case should be described as thrombocytopenia associated with posterior mediastinal hemangioma demonstrating findings suggestive of KMP. Routine blood test was performed on postoperative day 1, and the results showed a platelet count of 127 × 10⁹/L (Table 1), which was in the normal range. Routine blood examination performed on postoperative days 3, 5, and 6 revealed platelet counts in the normal range (Table 1). The patient’s chest drainage tube was removed on postoperative day 6, and she was discharged on postoperative day 7. She was instructed to undergo routine blood tests at 2, 4, and 8 weeks after discharge, particularly to assess platelet counts. Follow-up visits at each time point revealed platelet counts within the normal range (Table 1). The patient’s platelet count significantly improved during hospitalization, with levels rising from 17 × 10⁹/L to 152 × 10⁹/L on the day prior to surgery. However, the contribution of surgical intervention versus transfusion therapy to the recovery remains unclear. The patient received 3 units of red blood cells, 350 mL of plasma, and 2 therapeutic volumes of platelets intraoperatively, which may have helped improve the platelet count. Although the platelet count returned to normal levels post-surgery, it remains uncertain whether this recovery was due to surgical excision of the mass, transfusion support, or both. Given the significant blood product transfusion during the procedure, further investigations into the long-term response of platelet count posttransfusion were not conducted, and the patient’s hematologic status was limited to platelet counts. No long-term follow-up for hemangioma recurrence was performed, making it difficult to assess whether the patient’s condition improved solely due to surgical resection or if further interventions were required. Additionally, the status of other hematologic parameters (e.g. hemoglobin level, white blood cell counts, and coagulation factors) was not assessed during the postoperative period, which could have provided more insights into the patient’s overall recovery and any underlying hematologic abnormalities. Notably, there was an inconsistency in the size measurements of the mass between different imaging studies. CT performed 2 weeks prior to admission reported a mass size of 3.7 × 2.5 cm², whereas MRI performed on the first hospital day reported a size of 3.5 × 2.6 cm².

Discussion

Beyond its clinical implications, this case offers important educational value by illustrating how hemangiomas presenting in adulthood with thrombocytopenia can mimic KMP, leading to diagnostic uncertainty. A combination of patient's thrombocytopenia, elevated D-dimer, low fibrinogen levels, prolonged PT/APTT, and elevated LDH levels, initially appeared consistent with KMP; however, without pathological evidence of KHE or TA, the diagnosis remained presumptive rather than definitive. The association of thrombocytopenia with vascular tumor (suspected hemangioma in this case) further supported this diagnosis. Additionally, the presence of microangiopathic hemolytic anemia was consistent with the pathophysiological mechanisms of KMP. Although there was no immediate evidence of other vascular tumors, such as KHE or TA on imaging, the diagnostic workup was consistent with KMP based on the patient’s clinical and laboratory profile.

Notably, KMP was first recognized and summarized in 1940 in an infant with a large, rapidly expanding lesion in the thigh region that was associated with thrombocytopenia; the lesion in this case was a KHE. The combination of cutaneous and visceral KHE and TA with thrombocytopenia or consumptive coagulopathy is known as KMP, which commonly occurs in infancy or childhood and rarely during adulthood. ⁵ The cause of thrombocytopenia is believed to be the enhanced phagocytosis of platelets by the reticuloendothelial system. Hemangioma may produce platelet antibodies that destroy platelets. Additionally, the complex network of blood vessels in hemangioma promote platelet coagulation and entrapment within the tortuous hemangioma, resulting in rapid consumption of platelets.^6,7 Due to the concealability of visceral hemangioma, clinicians should concentrate on identifying potential vascular lesions Simultaneously, patients should undergo complete hematological examination, particularly platelet count assessment. ⁸ This case highlights the diagnostic pitfalls of hemangiomas in adults that mimic KMP and underscores the educational importance of cautious terminology and interpretation in the absence of histopathological confirmation.

However, this case does not meet the definitive diagnostic criteria for KMP, which requires the presence of KHE or TA and consumptive coagulopathy. Although thrombocytopenia was present, the lesion lacked the classic histological features of KHE or TA, and there was no conclusive evidence of consumptive coagulopathy, indicating that the diagnosis remained uncertain. Thus, this case should be interpreted as thrombocytopenia associated with posterior mediastinal hemangioma, with features overlapping KMP in the absence of sufficient evidence for a definitive diagnosis.

Owing to the rarity of KMP in adults, most expert consensus guidelines have focused on the treatment of KMP in infants or children. Conservative medical treatment plays an important role in preventing serious complications during KMP treatment. In the past, the first-line treatment was steroids. The main mechanism of action of steroids has not been fully studied; however, it inhibits fibrinolysis and prevents blood vessel regeneration in hemangioma lesions. Increasing the life span of platelets may be an important rationale for its use as the first-line treatment. ⁹ Currently, some experts have suggested steroids combined with vincristine as the first-line treatment. Vincristine directly affects hemangioma lesions by reducing tumor growth rate and restricting lesion size by inhibiting the growth of endothelial cells, increasing the apoptosis of endothelial cells, and reducing the generation of blood vessels. However, the usage and dose of vincristine are under study. ¹⁰

Surgical resection of the primary hemangioma is crucial in KMP treatment; however, owing to the hemodynamic instability associated with advanced-stage KMP, surgical treatment is not recommended during this period. Before surgical treatment, platelet transfusion is usually avoided except in case of active bleeding, which could lead to further consumption of platelets at the lesion site. This, in turn, may lead to more serious coagulation disorders; however, during the preparation period for surgery, cryoprecipitation treatment can be administered.^11,12

The pathological types of mediastinal tumors are very complex, and mediastinal hemangiomas account for <0.5% of all mediastinal tumors. Due to the specific anatomical location of these tumors, diagnosis and treatment remain challenging. The definitive diagnosis of mediastinal hemangioma depends on the combined assessment of imaging studies and pathological tissue analysis. ¹³ Owing to the unique location of posterior mediastinal tumors, most of them are diagnosed as neurogenic tumors. Therefore, preoperative plain CT, enhanced CT, or MRI are crucial. ¹⁴ Surgery is the fundamental treatment for mediastinal hemangioma. Surgical suture and ligation or complete resection of the hemangioma are currently the mainstay methods for resolving posterior mediastinal hemangioma. After complete resection of the hemangioma, immunohistochemistry and biopsy can be performed to further refine the diagnosis.^15,16 Although most mediastinal hemangiomas are benign, their rarity and complexity warrant long-term monitoring of the lesion site to prevent hemangioma recurrence. ¹⁷

This report presented a case of adult-onset KMP complicated with posterior mediastinal hemangioma. Initially, only the patient’s platelet count was monitored to ensure that it remained within the normal range; long-term platelet-raising therapy did not achieve good outcomes, and the local hospital could not establish a definitive diagnosis. A posterior mediastinal mass was discovered accidentally during a physical examination, warranting surgical resection. After admission, symptomatic treatment was administered to resolve thrombocytopenia symptoms. Intraoperatively, the mass was identified as an oval hemangioma with a size of 3.5 × 2.6 cm². The hemangioma ruptured and bled during the exploration; it was sutured, and the lesion was removed. The patient’s platelet count was monitored for a long time postoperatively and, without additional treatment, the platelet count remained in the normal range at multiple time points. Notably, the size of the mass varied across different imaging studies. The contrast-enhanced CT scan performed 2 weeks prior to admission reported a size of 3.7 × 2.5 cm², whereas MRI performed on the first hospital day reported a size of 3.5 × 2.6 cm². This discrepancy may be attributed to differences in the imaging modalities, potential changes in the mass owing to the patient’s clinical condition, or the timing of imaging studies. Further imaging or follow-up studies could be considered for a more accurate estimation of the tumor size and behavior over time. Due to the vascular nature of the suspected hemangioma and its associated bleeding risk, focused attention was given to intraoperative anesthesia management. The patient was carefully monitored during the induction and maintenance of general anesthesia, with particular attention to blood loss and hemodynamic stability. Intraoperatively, 3 units of red blood cells, 350 mL of plasma, and 2 therapeutic volumes of platelets were transfused to address any significant blood loss. No anesthesia-related complications were observed during the procedure. Given the high bleeding risk, the anesthesiologist and surgical team worked collaboratively to ensure adequate blood product management and minimize any perioperative complications related to coagulopathy and thrombocytopenia.

The present report describes an atypical case of KMP in an adult patient, which is relatively rare in the literature. The lesion was located in the posterior mediastinum, a region often concealed. The preoperative diagnosis of mediastinal hemangioma should be made based on various imaging studies to facilitate the planning of an appropriate surgical strategy. When the depth and width of the basal part of the hemangioma are within a manageable range, clinicians should aim for complete resection of the lesion.

Although this case provides a detailed overview of the surgical management of a mediastinal hemangioma, the inappropriate application of the KMP diagnosis in this adult patient diminishes its educational value. KMP is exceedingly rare in adults and requires robust diagnostic criteria that were not fully met in this case. KMP typically involves a combination of KHE or TA with thrombocytopenia and consumptive coagulopathy. In this instance, the lesion identified was a mediastinal hemangioma, lacking the specific histological features of KHE or TA. Furthermore, the patient did not present with the characteristic consumptive coagulopathy manifested in true KMP cases. Therefore, it is crucial to avoid misapplying the KMP diagnosis to prevent the perpetuation of medical misinformation. This misapplication could lead to confusion regarding the nature of adult-onset KMP, which remains an extremely rare and poorly understood phenomenon. True KMP in adults is exceedingly rare and requires careful diagnostic workup, including histopathological evaluation and clinical features that were not conclusively demonstrated in this case. Although thrombocytopenia was present, it was more likely secondary to the hemangioma’s vascular nature, rather than a classic indicator of KMP. This distinction is vital to ensure that appropriate treatment is provided and that adult cases of KMP are not misdiagnosed or inappropriately treated based on incomplete criteria. Given the rare and complex nature of KMP, particularly in adult patients with posterior mediastinal hemangiomas, clinicians should approach similar cases with caution. Further diagnostic workup, including molecular genetic testing and histopathological analysis, is critical for accurate diagnosis and optimal patient management. This case highlights the need for continued research into rare vascular tumors and coagulopathies in adults.

Limitations

Although the patient was carefully evaluated for thrombocytopenia, the diagnostic workup was incomplete, particularly lacking molecular genetic analysis and immunohistochemical evaluation of the hemangioma. Additional immunohistochemical staining (CD31, CD34, D2-40, Ki-67, and Factor VIII) was performed; however, these markers alone cannot fully exclude KHE or TA. Moreover, molecular testing for PIK3CA and HRAS mutations, which could have provided greater diagnostic clarity, was not conducted. The exact cause of the thrombocytopenia could not be definitively established. Although the platelet count normalized postoperatively, it remains unclear whether this was directly attributable to the surgical resection or the intraoperative transfusion of platelets, red blood cells, and plasma. In the absence of long-term follow-up, we could not determine whether the improvement in the platelet count sustained beyond the 8-week postoperative period. Moreover, no radiological surveillance was performed after discharge; therefore, the possibility of tumor recurrence cannot be excluded. The absence of long-term follow-up for identifying hemangioma recurrence also limits the ability to assess the risk of tumor regrowth. Finally, the hematologic evaluation did not include a broader workup to identify other possible causes of thrombocytopenia, such as bone marrow failure and autoimmune disorders.

This case highlights several important points. First, posterior mediastinal hemangioma with thrombocytopenia may present with clinical and laboratory features that mimic KMP, creating a diagnostic pitfall. Second, confirmation of KMP requires not only clinical and hematologic abnormalities but also pathological and molecular evidence of KHE or TA, which was not available for this patient. Finally, this case should not be interpreted as proof of adult-onset KMP, rather an illustration of how hemangioma-associated thrombocytopenia can resemble KMP and lead to diagnostic ambiguity.

Conclusion

This report described the case of an adult patient with a posterior mediastinal mass, initially suspected to be a neurogenic tumor but ultimately diagnosed as a hemangioma. The patient’s thrombocytopenia, accompanied by other laboratory findings, such as low fibrinogen and elevated D-dimer levels, raised the possibility of consumptive coagulopathy suggestive of KMP. However, the absence of classic histological features of KHE or TA and the lack of clear consumptive coagulopathy caution against definitively classifying this case as KMP. Although the patient’s platelet count normalized postoperatively, the contribution of surgical resection versus transfusion support to this recovery remains unclear. Further molecular testing and long-term follow-up are warranted to fully understand the underlying pathology and guide treatment strategies in such rare presentations.

In this case, KMP was suspected but not confirmed. In adult patients, diagnostic uncertainty must always be considered and caution exercised before establishing a definitive diagnosis of KMP.