Extraskeletal Mesenchymal Chondrosarcoma in Nasal Cavity: A Rare Case Report

Abstract

Extraskeletal mesenchymal chondrosarcoma (ESMC) originate from the nasal cavity have rarely been reported, especially its imaging features, which makes the preoperative diagnosis difficult. Here, we report the clinical, computed tomography, and magnetic resonance imaging features of a 60-year-old female patient with pathologically confirmed ESMC in the nasal cavity to help provide more reference for diagnosis before operation. Extraskeletal mesenchymal chondrosarcoma in the nasal cavity demonstrates typical imaging features, such as mesh-like enhancement, calcification, hemorrhage, necrosis, cystic degeneration, and so on.

Introduction

Extraskeletal mesenchymal chondrosarcoma (ESMC) is a rare special subtype of chondrosarcoma, and the one that originates from the nasal cavity is even rarer. ^1,2 Extraskeletal mesenchymal chondrosarcoma is regarded as a high-grade sarcoma with a high incidence of metastasis, ³ and the adjacent vital structures are vulnerable to invasion, which leads to a poor prognosis if treated insufficiently. ⁴ Therefore, the early and accurate diagnosis, as well as the preoperative accurate positioning and invasion scoping, is particularly necessary. However, a literature search identified only a few cases of ESMC arise from the nasal cavity ⁵ or sinonasal tract. ^6,7 Reports related to its imaging features were even rare, which makes the preoperative diagnosis difficult. In this report, we focus on describing the computed tomography (CT), and magnetic resonance imaging (MRI) features of ESMC in the nasal cavity to help provide more reference for preoperative diagnosis.

Case Report

We reported the case of a 60-year-old female patient who presented with a 20-day history of nasal congestion, swelling of the right eye, and occasionally bloody discharge. Nasal endoscopy revealed a pink neoplasm blocked the right nasal cavity.

Images of CT had revealed a soft tissue mass blocked the right nasal cavity with a small patchy slightly high density in the lesion, which indicated to be calcification. The lesion invaded the ethmoid sinus and frontal sinus upward and extended outward to the orbit (Figure 1A). The medial wall of the right maxillary sinus tends to be thinning due to compression, and bone destruction of the ethmoid was detected.

Figure 1.

Radiological and pathological images from a 60-year-old female patient with extraskeletal mesenchymal chondrosarcoma (ESMC). (A) Unenhanced computed tomography (CT) showed a soft tissue mass in the right nasal cavity. Note the patchy calcification inside the tumor (attenuation value = 235.10 Hu). (B and C) 3.0T magnetic resonance (MR) images demonstrated that the tumor is hypointensity on T1-weighted imaging (T1WI) and mixed hyperintensity on fat-suppressed T2-weighted imaging (T2WI). Note the mesh-like isointensity areas inside the tumor. (D) The tumor was mesh-like enhanced obviously. (E and F) No obvious limitation of diffusion was observed on the diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) map. (G) Time-signal intensity curve (TIC) of the tumor revealed an upward type. (H) Histopathological examination revealed that the tumor mainly consists of 2 components: hyaline tumoral cartilage island and undifferentiated small round interstitial cells. Note there were multiple vascular clearances inside (hematoxylin and eosin [H&E], ×400).

Images of 3.0T MRI had demonstrated a tumor with heterogeneous low signals on T1-weighted imaging (T1WI; Figure 1B) and mixed high signals on T2-weighted imaging (T2WI; Figure 1C). Moreover, mesh-like isointensity areas inside of the tumor were detected. After intravenous injection of Gd-diethylenetriamine pentaacetic acid (Gd-DTPA) , the tumor demonstrated obvious mesh-like enhancement (Figure 1D). On the diffusion-weighted imaging sequence (b = 1000 s/mm ² ), no obvious limitation of diffusion was observed (Figure 1E). Also, the tumor revealed high signals on the apparent diffusion coefficient maps (Figure 1F). The tumor’s boundary was clear with a size of 26 mm × 36 mm × 45 mm. High signals both on T1WI and T2WI were observed in the right frontal and maxillary sinus. The time-signal intensity curve of the lesion revealed an upward type (Figure 1G).

Then, a nasal endoscopic resection of the tumor was performed. The neoplasm was pink, firm, but not easily bleeding. There are white fish-like structures and brown liquefaction necrosis substances inside. Meanwhile, a large amount of hematocele was detected in the right maxillary sinus.

Histopathological examination revealed that the tumor mainly consists of 2 components: hyaline tumoral cartilage island and undifferentiated small round interstitial cells. There were also multiple vascular clearances inside the tumor (Figure 1H). Immunohistochemical analysis results were as following: MyoD1 (−), CK (−), CK5/6 (−), P63 (−), S-100 (+), CD56 (+), P40 (+), Desmin (−), Nestin (+), Vimentin (+), SMA (−), and MSA (−).

Discussion

Extraskeletal mesenchymal chondrosarcoma was first reported by Dowling in 1964, ¹ it is believed to originate from cartilage or chondrogenic mesenchymal tissue. Mesenchymal chondrosarcoma is a rare special subtype of chondrosarcoma, accounts for less than 1% of the total incidence, and the one that occurred in the extraskeletal system is even rarer. ^1,2 The majority of ESMC occurs in the soft tissue of the lower extremities, the orbit, meninges, and so on. ^1,2 A literature search identified only a few cases of ESMC originated from the nasal cavity ⁵ or sinonasal tract. ^6,7 Reports related to its imaging features were even rarer, which makes the preoperative diagnosis difficult.

Extraskeletal mesenchymal chondrosarcoma occurs frequently in people aged 20 to 30 years old, with a slightly female predominance. ⁸ The clinical manifestation of ESMC usually lacks specificity, which leads to difficulty in preoperative diagnosis. For this present 60 years old female patient, the main symptom is a stuffy nose with swelling of the right eye, thus easy to be misdiagnosed. Mesenchymal chondrosarcoma is regarded as a high-grade sarcoma in the grading systems of the French Federation of Cancer Centers Sarcoma Group, the National Cancer Institute, and the World Health Organization classification. Meanwhile, ESMC is prone to metastasis and could occur in the whole body. ³ The primary treatment modality of ESMC is radical surgery. ⁹ Therefore, an early and accurate diagnosis is particularly of the essence.

Computed tomography usually demonstrates a well-circumscribed mass of iso- or hypodensity, with stippled calcified areas, accompanied by osteosclerosis of the edge. ^{10 -12} It is reported that variable calcification is a key imaging feature of chondrosarcoma in the sinonasal and orbital region, and the calcification of mesenchymal chondrosarcoma was smaller with lower density. ¹³ The adjacent bone destruction is commonly seen. ¹³ The tumor is typically large in the axial skeleton but relatively smaller in the sinonasal tract. ⁸ The imaging features may be related to the location, pathological subtype, and grade of the tumor.

The MRI features of ESMC have rarely been reported ^{10 -12} which adds difficulty to our diagnosis. In the present case, the tumor demonstrated hypointensity on T1WI and mixed hyperintensity on fat-suppressed T2WI, with mesh-like isointensity areas inside. Images after gadolinium contrast revealed mesh-like enhancement. Combined with the pathology, we speculate the enhanced mesh-like part to be the solid component of the tumor, corresponding to the white fish-like structures seen in the gross specimen. The remaining part was speculated to be liquefaction necrosis substances revealed as hypointensity on T1WI and hyperintensity on T2WI. Moreover, the high signals demonstrated in the right frontal and maxillary sinus were considered to be hematocele. All these above features demonstrated that hemorrhage, necrosis, and cystic degeneration are commonly seen in ESMC originated from the nasal cavity.

Conclusion

Extraskeletal mesenchymal chondrosarcoma in the nasal cavity revealed typical imaging features, such as mesh-like enhancement, calcification, hemorrhage, necrosis, cystic degeneration, and so on. The combination of CT and MRI is the essence for the diagnosis of ESMC. Computed tomography is better in showing calcification and bone destruction, while MRI can offer more information on the tumor’s constituent.