Mesenchymal chondrosarcoma (MC) is an infrequent neoplasm, representing approximately 1% of all chondrosarcomas. Cytologic descriptions of MCs have been confined to rare case reports. In the current report, the authors describe their experience with the cytologic features of four MCs: two primary tumors and two metastatic lesions.
Four patients were diagnosed with MC at the authors' institution from 1994 to 2002. Three of four patients underwent fine-needle aspiration (FNA) biopsy as part of their diagnosis; in the fourth patient, imprint cytology was performed. Each tumor also received histologic confirmation.
The patients studied included three females and one male. In three patients, the tumor presented initially as a soft tissue mass; whereas, in the remaining patient, the MC presented in the tibia. FNA results demonstrated small, oval-to-spindled cells with high nuclear-to-cytoplasmic ratios. Cells occurred singly and in clumps in a background of basophilic extracellular matrix. Histologic examination of each lesion demonstrated biphasic tumors, including focal areas of relatively mature cartilage formation as well as a small cell population.
MC is a rare soft tissue tumor that occurs frequently in extraskeletal locations. FNA of these tumors can be diagnostic if the tumor is sampled appropriately and of critical features, such as the background extracellular matrix, are recognized. Given the propensity of these tumors to metastasize and the poor prognosis of patients with MC, early identification by FNA biopsy may allow earlier, more aggressive interventions.