CD8+ Mycosis Fungoides in Peripheral Blood; A Rare Finding

Cutaneous T cell lymphomas are mature lymphomas of T lymphocyte presenting with skin lesions and/or systemic manifestations. Majority of these cases show CD4+ phenotype and are classified as Mycosis Fungoides (MF)/Sezary syndrome (SS) spectrum.

Here we present a case of 74-year-old male patient, having no known comorbid, presented in Dr. Ziauddin Hospital, Karachi OPD with complains of generalized skin lesions, itching for 2 years, generalized weakness for 4 months and no lymphadenopathy or visceromegaly. CBC showed absolute lymphocytosis and absolute eosinophilia. Some lymphocytes exhibited cerebriform nuclei. CT scan neck, chest and abdomen showed bilateral enlarged superficial inguinal lymph nodes and multiple enlarged bilateral axillary lymph nodes. Skin biopsy was inconclusive. Immunophenotyping of peripheral blood was then performed which showed an aberrant T cell population showing positivity for CD3, CD8, CD2, CD25 and negative for CD4, CD45, CD5, CD30, CD56 with variable expression of CD7. Case was finalized as CD8+ Mycosis Fungoides with peripheral blood involvement.

These findings are very rare and highlight the importance of integrated approach to clinical course, morphological findings and other ancillary tests to be used in correlation with each other. These findings also highlight the diversity present in T cell malignancies in terms of immunophenotype.