The immutable relevance of myeloid sarcomas: Clinicopathological study of fourteen cases

An extramedullary myeloid tumor or chloroma is an infrequent manifestation of a myeloid neoplasm. It is considered an equivalent to an acute myeloid leukemia. It is confirmed through biopsy, where infiltrating neoplastic myeloid cells distort the parenchyma. A total of twenty-nine cases were diagnosed as MS between 198 and 2023. Upon re-evaluation, only fourteen cases fulfilled the criteria for MS. The most common differential diagnosis were lymphomas, leukemic infiltration, and extramedullary hematopoiesis. Few were isolated cases; the rest were in the context of progression of a myeloid neoplasm. The majority had a myelomonocytic morphology and immunophenotype. The most reliable markers were CD45, HLA-DR, CD68 and CD4. The study highlights the complexity and impact of an accurate diagnosis of a myeloid sarcoma.