Concurrent Hairy Cell Leukemia and Metastatic Merkel Cell Carcinoma

Abstract EN

Hairy cell leukemia (HCL) and Merkel cell carcinoma (MCC) are two rare malignancies with distinct cells of origin.

HCL is a lymphoid malignancy of mature B cells, and MCC derives from neuroendocrine cell origin.

HCL has a favorable prognosis with most patients achieving long-term remission and potential cure.

In contrast, MCC is an aggressive malignancy affecting the skin and can metastasize quickly with a dismal prognosis.

Immunocompromised patients, such as those with AIDS, posttransplant, and the elderly, have higher incidences than the general population, suggesting a possible immune mechanism.

We report a case where a patient presented with HCL and metastatic MCC synchronously.

This is the first reported case of these two rare malignancies occurring concurrently at initial presentation and may represent a role of immunosuppression in the pathogenesis of MCC.