Track
Case ReportsAbstract
Introduction:
Gamma-delta T-cell lymphocytes are a specialized subset of T-cells that play an important role in the innate immune response. They frequently lack major histocompatibility complex restrictions and behave in similar fashion to cytotoxic natural killer cells in the innate immune response. The WHO recognizes two classes of gamma-delta T-cell lymphomas: Primary cutaneous gamma-delta T-cell lymphoma (PCGDTL) which is the focus of this report, and hepatosplenic gamma-delta T-cell lymphoma.
Case:
A 44 year old female with history of rheumatoid arthritis presents to Dermatology clinic for one year of progressive violaceous plaques involving bilateral upper/lower extremities. A punch biopsy sent for dermatopathology evaluation demonstrates diffuse dermal and sub-cutaneous infiltrates of small-to-medium blue cells in a background of lymphocytes. There is minimal epidermal involvement. Immunohistochemistry reveals that the cells of interest are positive for CD3, CD56, TCR delta, and negative for CD4, CD7, CD8, and TCR beta F1, consistent with PCGDTL.
Discussion:
PCGDTL is a rare but deadly disease representing <1% of cutaneous lymphomas, with a median survival ~15 months. Due to the rarity of cases, there is a paucity of clinical trials or evidence-based guidelines to direct management. Treatment typically involves chemotherapy +/- stem cell transplantation, but many patients relapse with progressive decline. Poor prognostic factors include age >40 years, subcutaneous involvement/ulceration, central nervous system involvement, or hemophagocytic lymphohistiocytosis. A high index of suspicion is necessary for early recognition of PCGDTL, and further studies are warranted to help establish standardized treatment protocols and improve patient response rates.