Primary Cutaneous Peripheral T-Cell Lymphoma-Not Otherwise Specified, Initially Misdiagnosed as Mycosis Fungoides: A Case Report and Literature Review

This report describes the case of a 52-year-old male who presented with a four-month history of multiple hyperpigmented lesions, predominantly affecting the trunk and upper limbs. On physical examination, numerous hyperpigmented patches and plaques were observed, with the largest lesion located on the right flank. Systemic examination revealed hepatomegaly, splenomegaly (tip of the spleen palpable), and right inguinal lymphadenopathy. The patient had no history of fever, weight loss, or other chronic illness. Initially, he was labelled as a case of mycosis fungoides; however, a repeat cutaneous biopsy, along with a lymph node biopsy, established the diagnosis of Primary Cutaneous Peripheral T-Cell Lymphoma – Not Otherwise Specified (pcPTCL-NOS). The patient was treated with six cycles of the CHOP regimen, resulting in initial resolution of the lesions. A post-chemotherapy PET scan showed no evidence of residual disease. This case emphasizes the importance of a comprehensive clinical evaluation, as the patient's acute history and systemic involvement hinted towards a far more aggressive disease process. Through a series of investigations, the correct diagnosis was made, facilitating the timely initiation of appropriate management.