T-cell lymphoproliferative disorder of hand-mirror cell morphology presenting in an eosinophilic loculated peritoneal effusion, with omental "caking"

Cells with "hand mirror" morphology have not, to the best of our knowledge, been described in a primary effusion sample. This paper describes a case of T-cell lymphoma with eosinophilia in a patient with suspected peritoneal carcinomatosis. Rarely, a T-cell lymphoproliferative process may mimic primary peritoneal carcinomatosis, clinically suggested by a presentation in CT imaging of omental caking with bilateral massive loculated effusions in a patient without lymphadenopathy or splenomegaly. A 60 year old caucasian male presented with vague abdominal discomfort and increasing abdominal girth. Computed tomography showed a two centimeter thick omental cake and a small loculated effusion. The clinical presentation and imaging findings were most consistent with peritoneal carcinomatosis. Cytologic evaluation of the effusion was undertaken for diagnostic study. Rapid intraprocedural interpretation of the effusion sample showed a monomorphic population of cells with "hand-mirror" cell morphology exhibiting cytoplasmic extensions (uropodia) with 3-5 course dark cytoplasmic granules and a rim of vacuolated cytoplasm capping the opposing "mirror head" side. These cells were seen within a background of mature eosinophils. Flow cytometric evaluation of the ascites fluid demonstrated an atypical T-cell population with the following immunophenotype: CD2-, CD3+, CD4-, CD5-, CD7-, CD8+, CD56+. T-cell receptor (TCR) gene rearrangement was positive for clonal TCR-gamma gene rearrangement, supporting the diagnosis of a T-lymphoproliferative disorder. A T-cell lymphoproliferative process may present with "hand mirror" morphology in an effusion sample. These cells may show polar cytoplasmic vacuolization and 3-5 course granules within the "handle" of these unique cells. Cytoplasm shows peripheral constriction around the nucleus.