Primary soft tissue lymphomas: description of seven cases and review of the literature

The present study describes a series of primary soft tissue lymphomas, including immunohistochemical characterization by tissue microarray and cytogenetic profiling. Formalin-fixed, paraffin-embedded tissue samples were collected from patients who underwent soft tissue biopsy. Cases were selected according to the definition of primary soft tissue lymphoma as a lymphoid malignancy arising in soft tissues without evidence of other nodal or extranodal localization for a period of at least 6 months. Our series comprised seven patients with a mean age of 72 years. There were three diffuse large B-cell lymphomas (DLBCLs); one B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma; one DLBCL derived from follicular lymphoma; one ALK-negative anaplastic large cell lymphoma; and one follicular lymphoma. Immunohistochemical and molecular profiles were consistent with the histological diagnoses. The present study contributes to our knowledge about uncommon presentation of lymphoid neoplasms and confirms previously published clinical-pathological data. We present, for the first time, the complete immunohistochemical profile and molecular cytogenetic studies of these lymphoid neoplasms. A rare case of a primary soft tissue ALK-negative anaplastic large cell lymphoma is described in detail.