Primary mediastinal giant cell tumor

Case report of a giant cell tumor of the carotid sheath

Giant cell tumor of the soft tissue (GCTST) is a neoplasm with low malignant potential and typically affects the trunk and extremities. Herein, we present a case of a palpable right neck mass diagnosed as a GCTST of the carotid sheath in a 38-year-old woman. A review of the imaging characteristics as well as of the differential diagnoses of primary neoplasms of the carotid space is presented.

Giant Cell Tumor of Soft Tissue: A Rare Entity

Giant cell tumor (GCT) of the soft tissue (GCT-ST) is a rare, unusual primary soft tissue tumor that is completely distinct from, and should not be confused with, any giant cell-rich tumor of bone or soft tissue. Currently, GCT-ST is included in the group of so-called fibrohistiocytic tumors of intermediate (borderline) malignancy. The most common symptom is a painless, slow-growing mass in a superficial location. Computed tomography and magnetic resonance imaging show a solid, nonhomogeneous, frequently hemorrhagic mass. Differential diagnosis is broad and should include benign and malignant entities. The treatment and excision margins of GCT-ST are controversial. Incomplete surgical excision is usually followed by local recurrence. Biological behavior is unpredictable. Giant cell tumor of the soft tissue has shown a lower mean local recurrence rate compared to GCT of bone but has a higher metastatic and death rate. Therefore, close clinical follow-up is recommended. [Orthopedics. 2019; 42(4):e364-e369.].

Recurrent primary mediastinal giant cell tumor of soft tissue with radiological findings: a rare case report and literature review

Background

Giant cell tumor of soft tissue (GCT-ST), which histologically resembles GCT of bone, is a rare tumor. Usually, it is located in the lower extremities and trunk. GCT-ST, occurring in mediastinum, is extremely rare.

Case presentation

We encountered an 18-year-old Chinese woman who had mild dull pain on the left side of back. The following chest computed tomography (CT) showed a heterogeneous mass deeply situated in the posterior mediastinum with compression of the lung and invasion of the adjacent rib. On magnetic resonance imaging (MRI), the tumor exhibited predominantly slight hyperintensity on T2-weighted images and intensely heterogeneous enhancement on contrast-enhanced T1-weighted images. The whole body bone scan showed a mildly increased radiotracer uptake in the proximal portion of the left fifth rib, suggestive of local infiltration by the tumor. Surgical resection of the tumor was performed; subsequently, the tumor was histopathologically proved as GCT-ST. Three months after the operation, the patient developed a local recurrence. A brief discussion about the radiological findings, histopathological features, clinical behavior, and a detailed review of the relevant literature are presented.

Conclusions

To the best of our knowledge, this is the first case about recurrent primary mediastinal GCT-ST, moreover, this is the first report to introduce the MRI findings of primary mediastinal GCT-ST. The present case highlights the ubiquitous distribution of soft tissue giant cell tumor and the importance of considering this tumor in the differential diagnosis of posterior mediastinal neoplasms. Also, a long-term follow-up is required to properly assess the malignant potential of this tumor.

Mesenchymal tumours of the mediastinum--part I

The mediastinum is an anatomically defined space in which organs and major blood vessels reside with surrounding soft tissue elements. The thymus is an important organ in the mediastinum, and many of the masses encountered in the mediastinum are related to this organ. Most neoplasms diagnosed in the mediastinum are epithelial tumours (thymomas and thymic carcinomas), lymphomas or germ cell tumours. In contrast, soft tissue tumours of the mediastinum are rare. In 1963, Pachter and Lattes systematically reviewed soft tissue pathology of the mediastinum, covering the hitherto described [2, 226, 227] In this review, based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart, we provide an updated overview of mesenchymal tumours that may be encountered in the mediastinum.

Soft Tissue Giant Cell Tumor of Low Malignant Potential of Mediastinum

Giant cell tumor (GCT) is primarily a bone neoplasm. Rare origin of the tumor from soft tissues has been reported. Involvement of mediastinum by GCT is even rarer. We herein describe an interesting case of huge mediastinal tumor in a young man. Radiologically, no primary osseous lesion was present throughout the body. Morphologically, tumor resembles osseous GCT with increased mitotic activity. Hence, the case was diagnosed as soft tissue GCT of low malignant potential at the rare site of mediastinum. To the best of our knowledge, the present case is the fourth reported case. Pathologists and clinicians need to be aware of the rare diagnosis of GCT in mediastinum and should carefully evaluate the clinical and radiological findings.