[Pleural effusion as the first manifestation of pleural isolated myeloid sarcoma: a case report and literature review].

Objective: To analyze the clinic features of isolated myeloid sarcoma (IMS) involving the pleural cavity. Methods: A case of pleural isolated myeloid sarcoma (PIMS) with pleural effusion as the first manifestation was described. The related cases in literatures were reviewed with"myeloid sarcoma"and"pleural effusions"as the keywords to search China HowNet, Wanfang database and PubMed database. Results: A 59-year-old man complained of right chest pain for 2 months and worsening pain with distress and shortness of breath for 2 weeks. The chest CT scan showed pleural effusion on the right side. Flow cytometric analysis of pleural fluid showed that a population of blasts with CD34 expressing was 37.6% of the total nucleated cells. The pleural biopsy through medical thoracoscopy indicated lymphoproliferative lesions by pathological examination. Immunohistochemistry was performed on pleural histological sections and cell blocks of pleural effusions, which showed CD34 and CD117 positive expression. The diagnosis of PIMS was finally made. Two literature papers with 2 complete cases were found and reviewed. The 3 cases were analyzed. There were 2 males and 1 female. The age was 59, 51, 56 years respectively. One case was a patient with 3 weeks of right upper quadrant and epigastric pain, nausea, and weight loss. Cytological examination of the pleural fluid showed numerous poorly differentiated malignant cells. Histology from an open laparotomy in duodenal biopsies, gallbladder, and mesenteric lymph nodes supported the diagnosis of IMS. The other case was a patient with 6 weeks of dyspnea and a large swelling in the upper vestibular region. Thoracentesis showed 82% myeloid blasts in the pleural fluid. A gingival biopsy showed a diffuse infiltration by cells with a blastic appearance and supported IMS. Conclusion: PIMS was a very rare cause of pleural effusions. The cytological and histopathological evidences were useful to diagnose IMS involving the pleural cavity.