Totally implantable venous access port implantation in a breast cancer patient with situs inversus totalis: A case report

Abstract

Situs inversus totalis, a rare congenital condition characterized by complete mirror-image transposition of the thoracic and abdominal organs, has not previously been reported in patients with breast cancer. A 60-year-old woman with a 5-year history of left breast nodules was admitted. Contrast-enhanced breast magnetic resonance imaging and abdominal ultrasound revealed mirror-image transposition of the thoracic and abdominal organs. The patient was diagnosed with left breast cancer concomitant with situs inversus totalis. Preimplantation computed tomography revealed that the left internal jugular vein followed a straighter course to the right atrium than the right internal jugular vein. Under ultrasound guidance, a totally implantable venous access port was successfully placed via the left internal jugular vein. Neoadjuvant taxotere adriblastina cyclophosphamide chemotherapy was subsequently administered through the totally implantable venous access port before the patient underwent modified radical mastectomy for left breast cancer. Given the mirror-image anatomy, the anatomically relocated left internal jugular vein should be preferentially selected for totally implantable venous access port placement because of its more favorable anatomical course compared with the right internal jugular vein. To the best of our knowledge, this is the first reported case of totally implantable venous access port implantation in a patient with breast cancer and concurrent situs inversus totalis.

Background

According to GLOBOCAN 2020, female breast cancer is the most commonly diagnosed cancer worldwide and the fourth leading cause of cancer-related mortality. ¹ In China, the age-standardized 5-year survival rate for female breast cancer was estimated at 81.0% during 2019–2021, demonstrating a clear upward trend over time. ²

The pathogenesis of breast cancer has been extensively studied and involves genetic alternations, changes in hormonal homeostasis, and immune interference.^3–7 First-line treatment strategies for breast cancer include surgical resection, chemotherapy, and multimodal combination therapy. ⁸ Neoadjuvant chemotherapy is recommended for patients with triple-negative breast cancer(TNBC), those with human epidermal growth factor receptor 2 (HER2)–enriched tumors, and patients with lymph node metastasis or initially inoperable breast cancer. ⁸ Implantable venous access ports (PORTs) are the preferred vascular access devices for chemotherapy in patients with solid malignancies because they are associated with a lower risk of deep venous thrombosis and other catheter-related complications than peripherally inserted central catheters (PICCs). ⁹ In particular, totally implantable venous access ports (TIVAPs) are commonly used to facilitate neoadjuvant chemotherapy in patients with breast cancer. ¹⁰

Situs inversus totalis (SIT) is a rare congenital anatomical anomaly characterized by complete mirror-image transposition of the thoracic and abdominal organs, including the major blood vessels. ¹¹ SIT was first described in the 17th century, and its reported incidence ranges from approximately 1 in 8000 to 1 in 25,000 individuals.^12,13

A patient with breast cancer and concurrent SIT was admitted to our center, and neoadjuvant chemotherapy was recommended following evaluation by a multidisciplinary team (MDT). The anatomically relocated internal jugular veins (IJVs) were carefully assessed and compared, after which a TIVAP was successfully placed to facilitate chemotherapy. The clinical details of this unique case are presented herein. This work has been reported in accordance with the Surgical CAse REport (SCARE) 2023 criteria. ¹⁴

Case report

According to institutional policy, the Ethics Review Board of Zhejiang University School of Medicine does not require formal ethical approval for single case reports. Written informed consent was obtained from the patient for participation and publication of the clinical information presented in this study. A woman in her early 60 s and with a 5-year history of left breast nodules was admitted to the Department of Breast Surgery at The Second Affiliated Hospital, Zhejiang University School of Medicine in early 2024 because of marked enlargement of the left breast nodules over the preceding month. All patient details were deidentified. Ultrasound (US) revealed a hypoechoic mass measuring 3.7 × 1.88 × 1.81 cm in the upper inner quadrant of the left breast. The mass was regular in shape, with well-defined, smooth margins and a clear boundary, but demonstrated heterogeneous internal echogenicity. Color Doppler flow imaging (CDFI) revealed prominent clustered echogenic foci and increased intralesional blood flow signals. Mammography (molybdenum-target X-ray) classified the lesion as breast imaging-reporting and data system (BI-RADS) category 4C. Similarly, contrast-enhanced magnetic resonance imaging (MRI; Figure 1(a)) suggested a BI-RADS 4C lesion, indicating a high suspicion of malignancy. An ultrasound-guided core needle biopsy was subsequently performed to obtain tissue for histopathological examination. Pathological analysis showed estrogen receptor (ER) (+) progesterone receptor (PR) (+) Ki-67 20% HER2 (2+) breast cancer, and fluorescence in situ hybridization (FISH) test suggested HER2/chromosome enumeration probe 17 (CEP17) amplification (−) breast cancer.

Figure 1.

(a) Magnetic resonance image showing the concurrence of situs inversus totalis (SIT) and left breast cancer; (b) high-resolution computed tomography image showing successful insertion of TIVAP.

A MDT discussion was conducted, and TIVAP placement followed by neoadjuvant chemotherapy was recommended. Preimplantation high-resolution computed tomography (CT; images not shown) of the chest demonstrated mirror-image transposition of the thoracic organs, consistent with SIT. Selection of the vascular access site for TIVAP implantation was challenging. It is well established that the right IJV is typically larger in diameter and follows a more direct course to the superior vena cava, making it the preferred site for central venous cannulation under normal anatomical conditions. ¹⁵ In this case, we hypothesized that the anatomically relocated left IJV, because of the mirror-image anatomy associated with SIT, might exhibit morphological characteristics similar to those of a typical right IJV. Therefore, the left IJV was selected for cannulation. A TIVAP was successfully implanted via the left IJV under US guidance. The intraoperative position of the port and catheter was verified by X-ray imaging (Figure 2), and correct catheter tip placement was further confirmed by postoperative CT (Figure 1(b)). A clip was placed under US guidance to mark the left axillary lymph node suspected of metastasis. Neoadjuvant taxotere adriblastina cyclophosphamide (TAC) chemotherapy was subsequently administered through the implanted TIVAP. Following chemotherapy, the tumor mass remained stable state (SD), and the patient further underwent modified radical mastectomy of the left breast.

Figure 2.

The positions of implantable venous access device (PORT and the catheter were confirmed by X-ray imaging during the procedure.

Postoperative histopathological examination revealed invasive micropapillary carcinoma (IMPC), with metastases identified in 15 of 32 dissected lymph nodes, whereas the previously clipped target lymph node was negative for tumor involvement. Immunohistochemical analysis showed ER (80%, +), PR (−), Ki-67 2%, and HER2 (1+).

Discussion and conclusion

SIT and breast cancer

Breast cancer is a malignant tumor with substantial morbidity and mortality, imposing a significant burden on public health and healthcare systems worldwide. At our center, tailored treatment strategies are routinely formulated for individual patients based on MDT recommendations to ensure optimal, evidence-based care.

To the best of our knowledge, this is the first reported case of breast cancer complicated by SIT requiring TIVAP placement for neoadjuvant chemotherapy. This conclusion is based on a comprehensive PubMed search using the keywords “situs inversus totalis” or “SIT” combined with “totally implantable venous access port” or “TIVAP” and/or “breast cancer” or “breast tumor,” all of which yielded no previously published reports of a similar case. Sporadic cases of SIT have been reported in association with other malignancies, including gastric adenocarcinoma, ¹⁶ rectal cancer, ¹³ pancreatic cancer, ¹⁷ liver cancer, ¹⁸ and gallbladder adenosquamous carcinoma. ¹⁹ SIT is distinct from situs solitus, partial situs inversus, and situs ambiguus. ¹² It is characterized by a complete 180-degree mirror-image transposition of all thoracic and abdominal organs from left to right. It is reasonable to speculate that, in the context of complete mirror-image transposition, the breasts may also exhibit left–right reversal in their anatomical orientation. However, the concurrence of SIT and malignant tumors remains exceedingly rare, and only limited mechanistic investigations have explored any potential biological association between SIT and tumorigenesis. Several genes implicated in the pathogenesis of SIT have also been suggested to play potential roles in tumorigenesis, including NME7, ZIC3, LEFTYA, CRYPTIC, and ACVR2B. ²⁰ Further molecular and genetic investigations are warranted.

Challenge and recommendation for breast cancer surgeons

This is the first reported case of TIVAP implantation in a patient with breast cancer and concurrent SIT. The IJV and subclavian vein are the two principal venous access routes for TIVAP placement. A systematic review including 1086 patients demonstrated no significant differences in the incidence of major complications between these two approaches, including infection, catheter occlusion, port compression, catheter-related thrombosis, catheter malposition, extravasation, and catheter fracture. ²¹ IJV cannulation guided by anatomical landmark techniques has been widely practiced by vascular surgeons, with high reported success rates. ²² Imaging modalities such as color Doppler US, MR imaging, catheter venography (CV), and intravascular US remain essential adjunctive tools in anatomically complex cases, such as patients with SIT, to ensure accurate vascular assessment and safe procedural planning. ²³ At many centers, including ours, the standard approach for TIVAP placement is via the right IJV. However, in patients with SIT, the anatomically relocated left IJV should be selected, as it is presumed to offer anatomical advantages comparable to those of a typical right IJV under normal anatomy.

Strengths and limitations

This case is unique because of the rare congenital anomaly and the requirement for a PORT. However, an important limitation that should be acknowledged is that it involves a single patient.