Primary cutaneous pleomorphic small/medium-sized T-cell lymphoma in a young man

SIR, Primary cutaneous pleomorphic small/medium‐sized T‐cell lymphoma (PSMTCL) is a rare, recently recognized type of cutaneous T‐cell lymphoma (CTCL), clinicopathologically different from mycosis fungoides (MF)/Sézary syndrome.1,2 Only a few cases have been reported in the literature, and the treatment has not been well defined.1,3–5 The prognosis of PSMTCL can be favourable and it tends to occur in an older age group similarly to other types of CTCL.1,3–5 We report an additional case of PSMTCL occurring in a 19‐year‐old man. A 19‐year‐old man presented with a 3‐year history of a red‐purple, infiltrated plaque on the left side of the face. His past medical history was not contributory, and there was no history of a preceding patch‐like lesion of MF. The lesion was asymptomatic and measured about 5 × 7 cm. A skin biopsy showed a dense, dermal interstitial, folliculotropic, and focally epidermotropic infiltrate of small to medium‐sized, pleomorphic lymphocytes (Fig. 1). Alcian blue stain showed no mucin deposits. Immunophenotyping showed strong expression of CD2 and CD3. CD4 was expressed by 50% of the cells, but CD5, CD7 and CD8 were expressed by < 5% of the cells. CD30 was not expressed, and CD20 was expressed by approximately 20% of the cells. DNA extracted from the paraffin block showed gamma T‐cell receptor gene clonality on polymerase chain reaction analysis. Laboratory examinations including full blood count, peripheral blood smear review, erythrocyte sedimentation rate, liver function tests, antinuclear antibody, serum protein electrophoresis, immunoelectrophoresis, human T‐cell lymphoma virus type 1 and type 2, and Epstein–Barr virus serological tests, were within normal limits or negative. Chest X‐ray and computed tomography of the abdomen and pelvis showed no abnormalities. The patient was treated with local radiation therapy, which led to a complete remission of the lesion. He has now been free of disease for more than 14 months.