Follicular variant of peripheral T-cell lymphoma mimicking follicular lymphoma: A case report with a review of the Literature

Peripheral T-cell lymphoma (PTCL) with a follicular growth pattern is very rare. Herein, a case of follicular variant of PTCL in a 50-year-old man who complained of tonsillar and generalized lymph node swelling is reported. The resected tonsil revealed a vague nodular growth pattern of atypical cells, medium to large in size, with abundant pale cytoplasm. The lymphoma cells were CD3 ⁺ CD4 ⁺ CD5 ⁺ CD8 ^- CD10 ⁺ CD56 ^- CD57 ^- BCL6 ⁺ PD-1 ⁺ CXCL13 ⁺ and were associated with a meshwork of CD21 ⁺ follicular dendritic cells. Molecular studies revealed clonal rearrangement of the T-cell receptor gamma chain gene but not of the immunoglobulin gene. Cytogenetic analysis disclosed a complex abnormality in 18 of 20 cells with the exclusion of t(5; 9). These findings suggest that the present case is a follicular variant of PTCL derived from follicular T-helper cells.