SUBCUTANEOUS TISSUE INVOLVEMENT BY T-CELL LYMPHOMA - A REPORT OF 2 CASES

Background: T-cell lymphomas may involve the subcutaneous tissue as a manifestation of generalized disease. However, T-cell lymphomas rarely present with extensive involvement of the subcutaneous fat without ot her sites of disease. Observations: We describe 2 women who presented with fever and subcutaneous nodules or masses. In case 1, the nodules were generalized and did not respond to chemotherapy. The patient died 2 months after diagnosis. In case 2, the mass was large but localized and responded to chemotherapy. The tumor subsequently recurred in a c ervical lymph node 9 months later, and the patient was being treated w ith chemotherapy 15 months after initial diagnosis. Histologically, bi opsy specimens from both patients revealed malignant lymphoma involvin g the subcutaneous tissue. The dermis and epidermis were not involved. At low power the lesions resembled panniculitis, but high-power exami nation revealed cytologic atypia of the malignant lymphoid cells. Immu nohistochemical studies revealed T-cell lineage. In case 2, the neopla stic cells also expressed the CD30 antigen, were positive for Epstein- Barr virus RNA, and carried the t(2;5)(p23;q35) chromosomal translocat ion. We interpreted case 1 as an example of subcutaneous panniculitic T-cell lymphoma. We believe that case 2 is best classified as anaplast ic large cell lymphoma of T-cell lineage. Conclusions: A variety of T- cell lymphomas rarely present with only subcutaneous tissue involvemen t. Knowledge of this phenomenon and recognition of the cytologic atypi a of the lymphoid cells will help to prevent misdiagnosis.