Indolent CD8-positive T-LPD of the peripheral nervous system in a 19-year-old man.

A 19-year-old man presented with recurrent intermittent fever, progressive limbs weakness, numbness, and atrophy for 5 years. Biopsy of the sural nerve, spleen, lymph nodes, bone marrow and labial gland revealed that monomorphic small lymphoid cells infiltrated diffusely and that there was severe loss of large myelinated nerve fibers. Immunohistochemically, these cells were mainly CD8-positive T cells and were positive for CD3 and CD57. This patient was diagnosed as indolent CD8-positive T lymphoproliferative disorder (indolent CD8-positive T-LPD), emphasizing the need for a broad differential diagnosis under these conditions, and nerve biopsy should be performed.