Extramedullary Myeloid Sarcoma and Leukemia Cutis: An Unusual Presentation of Acute Myeloid Leukemia with t(10;11)(p12;q23) translocation (involving KMT2A/MLLT10) in a Postpartum Female

Extramedullary leukemia, or myeloid sarcoma, is a rare manifestation of acute myelogenous leukemia (AML) that typically occurs alongside bone marrow involvement. It is characterized by the infiltration of leukemic cells into extramedullary tissues such as the skin, soft tissues, and lymph nodes, often presenting as masses or nodules. This case emphasizes the diagnostic challenges associated with atypical presentations of AML with extramedullary involvement. Even after diagnosis and initiation of chemotherapy, the disease progressed, and leukemia cutis lesions developed, highlighting the aggressive disease.

A 36-year-old postpartum female, six months after delivery, presented with a three-month history of progressively enlarging nodules on the left side of her face. These nodules were initially misdiagnosed as a dental infection following the extraction of two teeth. Despite intervention, the nodules persisted and expanded, accompanied by worsening fatigue, shortness of breath, jaundice, and bruising, leading up to her hospital admission. The initial differential diagnosis included chronic infections such as osteomyelitis, granulomatous diseases like sarcoidosis, and neoplastic conditions like lymphoma.

Upon admission, physical examination revealed hard, non-tender nodules on the left cheek, significant left cervical lymphadenopathy, scleral icterus, and widespread bruising. Laboratory investigations revealed pancytopenia, with significant anemia, thrombocytopenia, and neutropenia. Elevated liver enzymes suggested hepatic involvement, raising the possibility of systemic disease. Imaging studies demonstrated multifocal masses in the facial soft tissues and extensive cervical lymphadenopathy, supporting a neoplastic process. A core biopsy of the cheek mass revealed diffuse infiltration of atypical myeloid cells, consistent with extramedullary AML with monocytic differentiation, corroborated by a bone marrow biopsy. Chromosomal analysis identified a t(10;11) translocation, indicative of an aggressive form of AML. The patient was initiated on induction chemotherapy with cytarabine and idarubicin.

Despite initial treatment, the patient developed new cutaneous lesions in April 2024, presenting as nodules and plaques across the skin. Biopsy of these lesions confirmed leukemia cutis, indicating persistent extramedullary disease.

This case highlights the atypical presentation of extramedullary AML with monocytic differentiation in a young postpartum female. The patient's clinical course, including facial nodules initially mistaken for a dental infection, underscores the diagnostic difficulties associated with extramedullary manifestations of AML. The presence of pancytopenia, jaundice, and systemic symptoms prompted a more comprehensive evaluation, leading to the correct diagnosis. This case underscores the importance of considering extramedullary leukemia in patients with unusual masses, especially when accompanied by systemic signs. The subsequent development of leukemia cutis after chemotherapy illustrates the aggressive nature of the disease and the need for continuous monitoring for relapse, which may require more intensive treatment approaches.