Background: Primary skeletal muscle lymphoma has been reported in very few cases. Although such imaging techniques as computed tomography and magnetic resonance imaging can supply diagnostic indications, the most reliable data are obtained by means of muscle biopsy investigations. Fine needle aspiration cytology (FNAC) has not been considered before for the diagnosis of muscle lymphoma.
Cases: In case 1, 60-year-old man presented with 2 masses in the pectoral muscle and neck. FNAC of the neck mass was performed. The diagnosis was non-Hodgkin's diffuse B-cell lymphoma of the muscle; the diagnosis was confirmed by surgical biopsy of the pectoral muscle. In case 2, a 70-year-old man presented with a mass in the quadriceps muscle. The results of FNAC aroused suspicion of lymphoma, and a muscle biopsy confirmed the presence of a non-Hodgkin's B-cell lymphoma. Immunohistochemistry identified it as non-Hodgkin's marginal zone B-cell lymphoma of MALT type.
Conclusion: FNAC can be a valuable starting point in muscle involvement by lymphoma because of the possibility of obtaining material by means of multiple aspirations without causing patients any discomfort.