First Case Report of a Huge Giant Cell Tumor of Soft Tissue Originating from the Retroperitoneum

Characteristics of primary giant cell tumor in soft tissue on magnetic resonance imaging: A case report

BACKGROUND

Primary soft tissue giant cell tumor (GCT-ST) is rare and has relatively low malignant potential. Most reports are pathological and clinical studies, while imaging studies have only been reported in cases of adjacent bone or with atypical cystic degeneration. With regard to the findings on magnetic resonance imaging (MRI) or ultrasonography, superficial masses can be further identified based on facial edema, skin thickening, skin contact, internal hemorrhage or necrosis and lobulation of the mass. Unlike deep-seated masses, MRI features do not always provide an accurate diagnosis for benign and malignant patients with superficial soft-tissue lesions. Thus, the application of diffusion-weighted imaging (DWI) to evaluate superficial soft tissue tumors is necessary.

CASE SUMMARY

A 36-year-old woman who had a suspected malignant tumor in the upper limb on ultrasound and computed tomography is reported. The signal intensity of the suspected tumor was heterogeneous on plain MRI; nodular and heterogeneous enhancement was observed in the tumor with irregular shapes and blurred margins on dynamic contrast-enhanced MRI. The lesion on DWI was hyperintense with a higher mean apparent diffusion coefficient (ADC) value. Finally, a GCT-ST was confirmed by pathology. This case suggests that GCT-ST should be distinguished as a benign soft tissue mass from giant cell-rich soft tissue neoplasms or malignant tumors.

CONCLUSION

The MRI features of the superficial GCT-ST in the upper limb included heterogeneous signal intensity within the lesion on T2-weighted image (T2WI) and T1-weighted fat-saturation spoiled gradient recalled echo (T1 FSPGR), nodular enhancement with blurred margins, irregular shapes, and a slow-increased enhancement. DWI could be used to differentiate a benign soft tissue mass from a malignant mass by the mean ADC value and provide more radiologic-pathologic information for the diagnosis of GCT-ST. Comprehensive imaging of primary GCT-ST could help complete tumor resection, and in turn likely prolong survival after surgery.

Primary Giant Cell Tumors of the Lung: A Clinicopathologic and Immunohistochemical Study of 3 Cases

Three cases of primary giant cell tumors of the lung akin to those described in the soft tissues are presented. The patients are 3 men between the ages of 43 and 54 years who presented with nonspecific symptoms of cough, chest pain, and shortness of breath. None of the patients had any prior history of malignancy anywhere else. Diagnostic imaging disclosed the presence of an intrapulmonary mass. All the patients underwent lobectomy. Grossly, the tumors were described as solid, slightly hemorrhagic, and measuring between 1.8 and 2.4 cm in greatest diameter. Histologically, the tumors were characterized by a dual population of multinucleated giant cells admixed with a mononuclear proliferation. Nuclear atypia was mild to moderate, and mitotic activity varied but was under 5 mitotic figures per 10 high power fields. Immunohistochemical stains showed positive staining for vimentin, CD68, and cathepsin K, whereas the tumors were negative for keratin, TTF-1, p40, S-100 protein, and SABT-2. Clinical follow-up was obtained in 2 patients who have remained alive and without evidence of recurrence or metastasis up to 12 months after surgery. One patient was lost to follow-up. The current neoplasms represent a tumor that to the best of our knowledge has not been reported as a primary neoplasm of the lung. The cases herein described represent an unusual occurrence and should be maintained in the differential diagnosis of primary pulmonary tumors rich in multinucleated giant cells.

Malignant giant cell tumor in the left upper arm soft tissue of an adolescent: A case report

BACKGROUND

Giant cell tumor of soft tissue (GCT-ST) is an extremely rare low-grade soft tissue tumor that is originates in superficial tissue and rarely spreads deeper. GCT-ST has unpredictable behavior. It is mainly benign, but may sometimes become aggressive and potentially increase in size within a short period of time.

CASE SUMMARY

A 17-year-old man was suspected of having a fracture, based on radiography following left shoulder trauma. One month later, the swelling of the left shoulder continued to increase and the pain was obvious. Computed tomography (CT) revealed a soft tissue mass with strip-like calcifications in the left shoulder. The mass invaded the adjacent humerus and showed an insect-like area of destruction at the edge of the cortical bone of the upper humerus. The marrow cavity of the upper humerus was enlarged, and a soft tissue density was seen in the medullary cavity. Thoracic CT revealed multiple small nodules beneath the pleura of both lungs. A bone scan demonstrated increased activity in the left shoulder joint and proximal humerus. The mass showed mixed moderate hypointensity and hyperintensity on T1-weighted images, and mixed hyperintensity on T2-weighted fat-saturated images. The final diagnosis of GCT-ST was confirmed by pathology.

CONCLUSION

GCT-STs should be considered in the differential diagnosis of soft tissue tumors and monitored for large increases in size.