Giant cell tumor of soft tissue with pulmonary metastases: pathologic and cytogenetic study

Giant Cell Tumor of Soft Tissue: An Updated Review

Giant cell tumor of soft tissue (GCTST) is a locally aggressive mesenchymal neoplasm of intermediate malignancy that predominantly occurs in the superficial soft tissue of the extremities. It is histologically similar to a giant cell tumor of bone (GCTB) and shows a mixture of round to oval mononuclear cells and osteoclast-like multinucleated giant cells. Currently, immunohistochemistry plays a very limited role in the diagnosis of GCTST. Primary or secondary malignant GCTST has recently been described and tumors exhibiting high-grade histological features demonstrate higher rates of distant metastasis. GCTST lacks the H3-3A gene mutations that are identified in the vast majority of GCTBs, suggesting a different pathogenesis. Surgery is the standard treatment for localized GCTST. Incomplete surgical resection is usually followed by local recurrence. Radiation therapy may be considered when the close proximity of critical structures prevents microscopically negative surgical margins. The systemic treatment options for advanced or metastatic disease are very limited. This review provides an updated overview of the clinicoradiological features, pathogenesis, histopathology, and treatment for GCTST. In addition, we will discuss the differential diagnosis of this peculiar neoplasm.

Giant cell tumor of soft tissue of the nasopharynx: A case report

Primary soft tissue giant cell tumors are rare. Although these tumors resemble their osseous counterparts, sequencing studies have suggested that these two may be genetically distinct. Treatment guidelines are less clear for this tumor type compared to giant cell tumor of the bone. Surgical excision is the standard of treatment; but for those with unresectable disease treatment options are less certain. For patients with unresectable tumors, the use of bisphosphonates and RANK-L directed biologic therapy have been described in the literature. We report a case of a nasopharyngeal giant cell tumor, which is an uncommon presentation of a rare soft tissue tumor. While surgery is the preferred treatment for this disease, the location of this tumor precluded resection. This has prompted the decision to employ systemic treatment with Zoledronic acid and subsequently Denosumab for the treatment of this patient.

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.].

Giant cell tumor of soft tissue is genetically distinct from its bone counterpart

Giant cell tumors of bone are locally aggressive bone neoplasms with a predilection for young adults. Histologically, they are composed of histiocytoid to spindled mononuclear cells, admixed with numerous large osteoclastic giant cells. Giant cell tumors of soft tissue are rare tumors that bear striking histological resemblance to giant cell tumors of bone and might be regarded as a soft tissue analog thereof. Point mutations of the H3F3A gene (coding for a histone H3.3 protein) at the Gly34 codon, mostly G34W resulting from a GGG>TGG nucleotide change, have recently been identified in a vast majority of giant cell tumors of bone. To delineate the possible pathogenic linkage between both tumor types, we analyzed the H3F3A genotypes in a series of 15 giant cell tumors of soft tissue by Sanger sequencing and found no mutation in any case. We then sequenced cognate histone H3 genes with an identical nucleotide sequence ('GGG') at the codon Gly34, including the H3F3B, H3F3C, HIST2H3A, HIST2H3C, and HIST2H3D genes, and no somatic mutation was detected. These results reveal that giant cell tumors of soft tissue are probably genetically distinct from their bone counterparts and suggest that they might be pathogenically unrelated. Given the prominence of non-neoplastic cells in these tumors and the limitations of the current study, however, analyses using more sensitive techniques might be required to solve the issue.

Nonepithelial skin tumors with multinucleated giant cells

Recognition of the different types of multinucleated giant cells in neoplastic and pseudotumoral lesions of the skin may be helpful in the differential diagnosis of these tumors. In this review, we will analyze the different types of multinucleated giant cells that can be found in nonepithelial cutaneous tumors and, more importantly, the clinicopathological context in which they are found. Touton giant cells are typically present in juvenile xanthogranuloma, necrobiotic xanthogranuloma, and some subtypes of xanthomas. Giant cells with a ground glass appearance are typically present in the solitary reticulohistiocytoma and multicentric reticulohistiocytosis. Osteoclast-like cells are found in giant cell tumors (GCT) of soft parts, plexiform fibrohistiocytic tumor, and atypical fibroxanthoma. Floret-like cells are present in giant cell fibroblastoma, pleomorphic lipoma, multinucleate cell angiohistiocytoma, and giant cell collagenoma.

Tumors of the foot and ankle: a single-institution experience

Tumors of the foot and ankle are rare, and the particular clinicopathologic features, therapeutic approach, and outcomes in this setting are not well established. From January 2000 to December 2010, 72 patients with primary musculoskeletal tumors of the foot and ankle, both benign and malignant, were treated at a single institution. Of the 72 patients, 56% were female. The median age was 52 years. Of the 72 tumors, 62 (86.11%) were located in the foot and 10 were located in the ankle; 63 (87.5%) were soft tissue tumors and 9 (12.5%) were bone tumors. Overall, 56 (78%) were benign tumors and 16 (22%) were malignant tumors. The most frequent soft tissue and bone diagnosis was giant cell tumor. The median follow-up period was 49 months. The vast majority of the tumors were located in the foot. Benign tumors were dominant, outnumbering malignant tumors by more than 3 to 1. The diversity of the histologic benign types was evident, with giant cell tumor, angiomyoma, and lipoma the most frequent. Regarding the malignant tumors, a clear male predominance was present, the median age was 45 years, and the most frequent tumor was synoviosarcoma. The 9-year overall and disease-free survival rate was 65% and 40%, respectively.

Fibrohistiocytic tumors and related neoplasms in children and adolescents

Fibrohistiocytic tumors (FHTs) in children and adolescents range from the benign fibrous histiocytoma, or dermatofibroma, to a variety of intermediate and malignant neoplasms, such as dermatofibrosarcoma protruberans and high-grade undifferentiated pleomorphic sarcoma (malignant fibrous histiocytoma). Those tumors as a group are comprised of fibroblasts, myofibroblasts, and histiocytes-dendritic cells with a variably prominent inflammatory infiltrate consisting of lymphocytes and eosinophils. Dendritic cells are also a major constituent of another group of neoplasms that include Langerhans cell histiocytosis, follicular and interdigitating cell sarcomas, and juvenile xanthogranuloma. These latter tumors are considered in this discussion for the sake of differential diagnosis and their possible histogenetic relationship to FHTs. Recent studies have suggested that the relationship between the fibroblast and histiocyte in the FHTs may reflect the intrinsic capacity to transdifferentiate from one to the other morphologic and functional state. The so-called "facultative fibroblast," as a cell with fibroblastic and histiocytic properties, was discussed in the context of the fibrous xanthoma 50 years ago. Possibly the entire histogenetic concept of FHTs should be reconsidered in light of current studies.

Modern interpretation of giant cell tumor of bone: predominantly osteoclastogenic stromal tumor

Owing to striking features of numerous multinucleated cells and bone destruction, giant cell tumor (GCT) of bone, often called as osteoclastoma, has drawn major attractions from orthopaedic surgeons, pathologists, and radiologists. The name GCT or osteoclastoma gives a false impression of a tumor comprising of proliferating osteoclasts or osteoclast precursors. The underlying mechanisms for excessive osteoclastogenesis are intriguing and GCT has served as an exciting disease model representing a paradigm of osteoclastogenesis for bone biologists. The modern interpretation of GCT is predominantly osteoclastogenic stromal cell tumors of mesenchymal origin. A diverse array of inflammatory cytokines and chemokines disrupts osteoblastic differentiation and promotes the formation of excessive multi-nucleated osteoclastic cells. Pro-osteoclastogenic cytokines such as receptor activator of nuclear factor kappa-B ligand (RANKL), interleukin (IL)-6, and tumor necrosis factor (TNF) as well as monocyte-recruiting chemokines such as stromal cell-derived factor-1 (SDF-1) and monocyte chemoattractant protein (MCP)-1 participate in unfavorable osteoclastogenesis and bone destruction. This model represents a self-sufficient osteoclastogenic paracrine loop in a localized area. Consistent with this paradigm, a recombinant RANK-Fc protein and bisphosphonates are currently being tried for GCT treatment in addition to surgical excision and conventional topical adjuvant therapies.