Soft tissue giant cell tumor of low malignant potential: A proposal for the reclassification of malignant giant cell tumor of soft parts

Author(s): Folpe AL, Morris RJ, Weiss SW


Although "giant cell tumor of soft parts" has traditionally been considered a single entity as reflected in the original term "malignant giant cell tumor of soft parts (MGCT)" and later by the term "malignant fibrous histiocytoma, giant cell type" the degree of atypia and mitotic activity varies in this group, suggesting biologic heterogeneity. The clinicopathologic features of 31 tumors meeting the traditional criteria of MGCT but having only mild to moderate nuclear atypia are presented. Patients with these tumors (19 females; 12 males) ranged in age from 14 to 84 years (mean, 40 years) and presented with masses of involving either superficial (n = 16) or deep (n = 13) soft tissue. Most occurred on the arm or hand (n = 16) and ranged in size from 0.7 to 6.5 cm (mean, 2.1 cm). The tumors consisted of sheets and nodules of rounded mononuclear cells that blended with spindled cells and benign osteoclastic giant cells. Pleomorphic giant cells were absent. Osteoid was noted in 10 cases, but features typically associated with tenosynovial giant cell tumors (such as dense stromal hyaline, siderophages, and xanthoma cells) were nearly always absent. Mitotic figures ranged from 1-10/10 HPF (mean, 2-3/10 high-powered field), and angiolymphatic invasion was present in 10 cases. Necrosis was absent, however. The mononuclear cells expressed CD68, tartrate-resistant acid phosphatase, and smooth muscle actin, but lacked CD45, S100 protein, desmin, and lysozyme, an immunophenotypic profile identical to that of giant cell tumor of bone. Follow-up information in 19 patients (mean, 3 yrs; median, 1-7 yrs) indicated recurrences in four patients, but none developed metastasis. This behavior contrasts significantly with the high-grade behavior traditionally associated with MGCT of soft parts. These giant cell tumors can be consistently recognized by the lack of cytologic atypia even in the face of mitotic activity and vascular invasion. Although their long term metastatic risk is not fully defined, we propose they be termed "giant cell tumors of low malignant potential" and regarded as the soft tissue analogue of giant cell tumor of bone. The term "malignant giant cell tumor of soft parts" or giant cell malignant fibrous histiocytoma should be restricted to histologically high-grade lesions.

Similar Articles

Mucinous cystic neoplasms of the mesentery: A case report and review of the literature

Author(s): Metaxas G, Tangalos A, Pappa P, Papageorgiou I

Mesenteric cyst: A rare intra-abdominal tumour

Author(s): Pithawa AK, Bansal AS, Kochar SPS

Mesenteric cystic neo formation: Report of two cases

Author(s): Saviano MS, Fundaro S, Gelmini R, Begossi G, Perrone S, et al.

Mesenteric cysts toward less confusion? Dig Surg 17: 323-328

Author(s): de Perrot M, Bründler MA, Tötsch M, Mentha G, Morel P

Retroperitoneal and intra-abdominal sarcoma

Author(s): Liles JS, Tzeng CWD, Short JJ, Kulesza P, Heslin MJ

Early management of mesenteric cyst prevents catastrophes: A single centre analysis of 17 cases

Author(s): Prakash A, Agrawal A, Gupta RK, Sanghvi B, Parelkar S

Primary giant cell tumor of soft tissues: A study of 22 cases

Author(s): Oliveira AM, Dei Tos AP, Fletcher CD, Nascimento AG

Plexiform fibrohistiocytic tumor: Clinicopathologic analysis of 22 cases

Author(s): Remstein ED, Arndt CA, Nascimento AG

Dermal and subcutaneous variants of plexiform fibrohistiocytic tumor

Author(s): Zelger B, Weinlich G, Steiner H, Zelger BG, Egarter-Vigl E