A previously well 39-year-old female presented with heavy intermenstrual bleeding, lethargy, and bleeding gums. Anaemia (Hb 8.9) and thrombocytopenia (platelets 58) were present with a normal white cell count (8.9). The blood film revealed circulating blasts. She described a five-week history of infected ingrowing toenails affecting both great toes. These toes were bleeding and tender to touch with overgrowing granulation tissue (Image 1). Surgical excision of the ulcerated, necrotic tissue was performed, with avulsion of the toenails.
The excised tissue showed sheets and solid nodules of neoplastic cells with scanty cytoplasm and hyperchromatic round nuclei (Image 2). Immunostaining was strongly positive for myeloperoxidase (Image 3) and CD43, revealing its nature as a granulocytic sarcoma. Tissue culture grew multiple organisms. Following surgery, both great toes became necrotic and septicaemia developed, necessitating admission to ITU and amputation of her right great toe.
She consented to chemotherapy on the MRC AML 17 trial entering complete remission following one cycle of ADE (cytarabine, daunorubicin and etoposide). She did not have high risk disease but, despite completing three courses of chemotherapy and receiving radiotherapy to her remaining great toe, she had a rapid bone marrow relapse. Reinduction chemotherapy failed to achieve further remission and she subsequently died.
Extramedullary deposits of myeloid precursors are a relatively rare presentation of acute myeloid leukaemia. Most commonly lymph nodes, skin or bone are affected but they may occur at any site. They may be concurrent with hematological presentation of AML or precede or follow the diagnosis by months. Granulocytic sarcomas involving the extremities are exceedingly rare, with this manner of presentation not previously described.