Giant cell tumor of soft tissue of the colon: a case report and review of the literature

Abstract

Background: A giant cell tumor (GCT) is a benign neoplasm characterized by mixture of mononuclear cells and multinucleated cells. A GCT of soft tissue (GCT-ST) is developed in various extraosseous sites, but GCT-ST of the gastrointestinal tract is very rare. GCT-ST usually has a benign course, but rare cases reported malignant potential of the tumor. Therefore, complete resection is required to prevent local recurrence or distant metastasis.

Case presentation: A 53-year-old woman was admitted for follow-up colonoscopy who underwent the colorectal endoscopic submucosal dissection (ESD) of a laterally spreading tumor at the hepatic flexure 6 months ago. A colonoscopy showed a polypoid mass about 3.5 × 2.5 cm at the previous ESD site. As endoscopic finding showed a smooth multi-nodular tumor without submucosal invasion, we performed endoscopic mucosal resection. Based on pathological and immunohistochemical findings, the lesion was diagnosed as a GCT-ST in the colon. Follow-up colonoscopy performed 6 months later revealed no evidence of recurrence.

Conclusion: This is the first report of a GCT-ST identified in the colon. Although GCT-ST generally has a benign clinical course, complete resection should be performed to prevent local recurrence and metastasis.

Keywords: Case report; Endoscopic mucosal resection; Giant cell tumors; Soft tissue neoplasm.

Fig. 1

Initial colonoscopy. Colonoscopy image showing nodular mixed granular type of LST at the hepatic flexure (A). En-bloc resected tumor measuring 25 × 20 mm (B). Follow-up endoscopy performed after 3 months showing a fibrotic scar at the endoscopic submucosal dissection site (C)

Fig. 2

Follow-up colonoscopy. Colonoscopy image showing a circumscribed multi-nodular polypoid tumor (Paris classification Ip type) at the previous endoscopic submucosal dissection site (A). En-bloc resected specimen measuring 35 × 25 mm (B)

Fig. 3

Histopathological findings of endoscopic mucosal resection specimen. A mixture of mononuclear cells and multinucleated osteoclast-like giant cells were localized in the center of the tumor with diffused internal hemorrhagic necrosis (A). Remnant hyperplastic crypts is observed in the basal portion (B). In the high power, proliferating multinucleated osteoclast-like giant cells and mononuclear cells with vascular proliferation are evident (C, D). (Hematoxylin and eosin stain: A × 1.25; B × 4; C × 20; D × 20) (microscope model: Olympus BX43F/software: KOPTIC HKBasic × 64, 4.8.16384.20200113, resolution: 600 dpi)

Fig. 4

Immunohistochemical findings of the tumor. The tumor cells are immunoreactive for CD68 in the cytoplasm (A), but negative for CD34 (B), CD117 (C) and cytokeratin (D). (magnification: A × 100; B × 100; C × 100; D × 100) (microscope model: Olympus BX43F/software: KOPTIC HKBasic × 64, 4.8.16384.20200113, resolution: 600 dpi)

Fig. 5

Timeline. History timeline of the patient with giant cell tumor of soft tissue of the colon