Fine-needle aspiration cytology of mediastinal non-Hodgkin's nonlymphoblastic lymphoma

The histologic features of primary mediastinal non-Hodgkin's nonlymphoblastic lymphoma (NHL) are well described in the surgical pathology literature. However, the fine-needle aspiration (FNA) cytology of these lesions has not been characterized thoroughly.

FNA material from 12 patients with primary mediastinal NHL was reviewed. The series was comprised of 7 men and 5 women with a mean age of 42 years (age range, 26-65 years). All 12 patients underwent a mediastinal FNA as the initial step in their diagnostic evaluation. In some cases, flow cytometry or immunocytochemical studies were performed on the FNA material to render a definitive diagnosis.

On the basis of the cytomorphologic findings and ancillary studies performed on the FNA material, a diagnosis of malignant lymphoma (five cases), consistent with/suspicious for malignant lymphoma (four cases), or nondiagnostic/negative for lymphoma (three cases) was rendered for each case. In general, a definitive diagnosis of malignancy was established when there was cytomorphologic evidence of lymphoma and a monoclonal lymphoid population could be demonstrated by immunocytochemistry. Eleven of the 12 primary mediastinal non-Hodgkin's lymphomas were large cell lymphomas (LCL), and 1 was a composite lymphoma (LCL and Hodgkin's disease). In three of the LCL cases the neoplastic cells exhibited prominent nuclear hyperlobation in association with sclerosis.

A diagnosis of primary mediastinal NHL can be established with a high degree of accuracy on the basis of FNA cytology. The FNA cytomorphology of primary mediastinal NHL correlates with the spectrum of morphologic diversity associated with this entity in the surgical pathology literature.