Case report and literature review of pleural myeloid sarcoma.

rationaleMyeloid sarcoma (MS) is an extramedullary solid tumor composed of myeloid progenitor cells, which is rare in non-leukemic patients. Our research aims to enhance the understanding of the challenges in diagnostic and therapeutic of MS. PATIENT CONCERNS: A 61-year-old male was admitted to hospital presenting with "malignant pleural tumor diagnosed 2 months prior, accompanied by chest distress for over a month." DIAGNOSIS: Cytological analysis of pleural effusion confirmed malignant cells and supported by immunohistochemical results. Bone marrow biopsy showed 83.5% blasts, with flow cytometry indicating 56.32% tumor cells and the presence of the AML1-ETO fusion gene (FLT3-ITD+). Cytogenetic analysis revealed complex karyotypic abnormalities. INTERVENTIONS AND OUTCOMES: After treated with the Idarubicin-Cytarabine regimen and intrapleural cisplatin, bone marrow biopsy revealed residual tumor cells (0.46%). Further consolidation with the Idarubicin-Cytarabine regimen and additional cycles of azacitidine plus venetoclax and cytarabine plus venetoclax were administered. Unfortunately, the patient passed away following disease progression. LESSONS: Although pleural myeloid sarcoma is extremely rare, it must be included in the differential diagnosis for unexplained solid pleural masses, particularly when accompanied by pleural effusion. Upon diagnosis, comprehensive staging investigations, including bone marrow biopsy and flow cytometry, must be performed immediately. The successful management of such complex cases relies on the close collaboration of a multidisciplinary team, including radiologists, pathologists, hematologists, and thoracic surgeons. Radiologists identify atypical imaging features, pathologists confirm the diagnosis through precise immunophenotyping, and ultimately, hematologists formulate and execute the correct treatment plan.