Chloroma of perianal region masquerading as perianal abscess.

Chloroma, also called granulocytic sarcoma (GS) or Myeloid Sarcoma, is a rare malignant extra-medullary neoplasm of myeloid precursor cells. It is usually associated with myeloproliferative disorders but its appearance may precede the onset of leukaemia. The presence of a chloroma is certainly a sign of poor prognosis. We report a case of chloroma in a middle aged female without a prior history of leukemia in the perianal skin region with clinical diagnosis of perianal abscess. When there is no concomitant leukaemia, diagnosis of chloroma may be difficult. Differential diagnoses include acute lymphoblastic leukemia, large cell NHL, lymphoblastic lymphoma, Ewing's sarcoma and cutaneous T cell lymphoma.