Ferry J A, Pettit C K, Rosenberg A E, Harris N L
James Homer Wright Pathology Laboratories, Massachusetts General Hospital, Boston 02114.
Am J Clin Pathol. 1991 Nov;96(5):577-81. doi: 10.1093/ajcp/96.5.577.
When fungi infect the bone marrow, typically they are associated with granuloma formation and/or necrosis, and the fungi are found within histiocytes or admixed with necrotic debris. Recently two bone marrow biopsy specimens were encountered in which fungi were confined to the cytoplasm of megakaryocytes, a finding not previously reported in the literature. The first case was that of a 46-year-old man with pulmonary histoplasmosis and no known immunodeficiency. The second was that of a 38-year-old man with the acquired immune deficiency syndrome and cryptococcal meningitis. In the first case, many megakaryocytes contained fungal forms consistent with Histoplasma. In the second, one small cluster of megakaryocytes contained several budding yeast consistent with Cryptococcus. Neither marrow biopsy specimen had necrosis, granulomas, or histiocytic infiltration. In both cases, because of the unusual localization of the fungi, they were initially overlooked. The bone marrow may contain fungi even in the absence of abnormalities suggesting fungal infection on routinely stained sections. A silver stain or a periodic acid--Schiff stain should be performed on all marrow biopsy specimens in cases of known or suspected fungal infection outside the marrow. The phenomenon of megakaryocyte emperipolesis is well known, and this process may be responsible for the apparent ability of megakaryocytes to internalize fungi.
当真菌感染骨髓时，通常会伴有肉芽肿形成和/或坏死，且真菌可见于组织细胞内或与坏死碎片混合存在。最近遇到两例骨髓活检标本，其中真菌局限于巨核细胞的细胞质内，这一发现此前未见文献报道。第一例是一名46岁男性，患有肺组织胞浆菌病，无已知免疫缺陷。第二例是一名38岁男性，患有获得性免疫缺陷综合征和隐球菌性脑膜炎。在第一例中，许多巨核细胞含有与组织胞浆菌相符的真菌形态。在第二例中，一小群巨核细胞含有几个与隐球菌相符的芽生酵母。两份骨髓活检标本均无坏死、肉芽肿或组织细胞浸润。在这两例中，由于真菌的异常定位，最初均被忽视。即使在常规染色切片上没有提示真菌感染的异常情况，骨髓中也可能含有真菌。对于已知或疑似骨髓外真菌感染的病例，所有骨髓活检标本均应进行银染色或过碘酸-希夫染色。巨核细胞血细胞吞噬现象众所周知，这一过程可能是巨核细胞内化真菌的明显能力的原因。
