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9 - Grade/differentiation unknown, not stated, or not applicable
Dendritic reticulum cell sarcoma
Follicular dendritic cell tumor
Sarcoma of follicular dendritic cells
FDC sarcoma is a neoplastic proliferation of spindled to ovoid cells showing morphologic and phenotypic features of follicular dendritic cells.
This is a rare sarcomas arising from the follicular reticulum cells in the B-cell area of the lymph node and forming a node-based tumor. It can also present in extranodal sites such as spleen, tonsil, oral cavity, gastrointestinal tract, liver, soft tissue, mediastinum and skin. An inflammatory pseudo-tumor-like variant of FDC sarcoma originates as tumors in the liver or spleen, with the neoplastic spindled cells dispersed in a lymphoplasmacytic infiltrate.
Follicular dendritic cell (FDC) sarcoma presents as lymphadenopathy in one-half to two-thirds of cases, with one of the cervical lymph nodes being most often affected. The tumor can also present in a wide variety of extranodal sites, such as the tonsil, oral cavity, GI tract, soft tissue, skin, mediastinum, liver, and spleen. Common sites for metastases include lymph nodes, lung, and liver. Patients most often present with a slow-growing, painless mass, although patients with abdominal disease may present with abdominal pain. The tumors are often large, with a median size of 5 cm. Systemic symptoms are uncommon in conventional follicular dendritic cell sarcoma, but are common in the inflammatory pseudo-tumor-like variant. The behavior of FDC sarcoma is usually indolent, much like a low or intermediate-grade soft tissue sarcoma. Most patients are treated by complete surgical excision, with or without adjuvant radiotherapy or chemotherapy. Local recurrences occur in more than 50% of cases, and metastases occur in about 25% of patients such occurrences may be delayed for many years. At least 10-20% of patients ultimately die of the disease, often after a long period of time. Cases showing high-grade features (significant cytologic atypia, extensive coagulative necrosis, and a high proliferative index), large tumor size (greater than 6 cm), or intra-abdominal location can pursue a rapidly fatal course.
Definitive Diagnostic Methods
Immunoglobulin and T-cell receptor genes in germline configuration
Clusterin strongly positive
Epidermal growth factor receptor +
Corresponding ICD-9 Codes
202.9 Other and unspecified malignant neoplasms
Corresponding ICD-10 Codes
C96.7 Other specified malignant neoplasms of lymphoid, hematopoietic
Corresponding ICD-10-CM Codes
(effective October 1, 2014 U.S. only)
C96.4 Sarcoma of dendritic cells (accessory cells)