Rodriguez G, Barrera G P
Department of Pathology, School of Medicine, National University, Bogotá, Colombia.
Mycopathologia. 1996;136(2):71-4. doi: 10.1007/BF00437498.
Lobomycosis is a dermal mycosis produced by Loboa loboi. It gives rise to dermal granulomas in which giant cells phagocytose an overwhelming number of fungi. Intracytoplasmatic asteroid bodies (AB) have been observed in some giant cells. Their nature is unknown and they have been confused with the sporotrichotic AB. We studied 84 skin biopsies from 53 patients with lobomycosis, 7 by electron microscopy (EM). Immunohistochemistry with a polyclonal anti-Sporothrix schenckii antibody was performed in five biopsies. We found AB in the giant cells in 22 of the 84 biopsies on HE staining. They appeared as single eosinophilic intracytoplasmic structures surrounded by a clear empty space. This clear space did not appear when the biopsy was fixed with OSO4, thus indicating that it is lipid in nature, and that the vacuole is an artefact produced by lipid extraction. Under the EM, the AB consist of bundles of dense, filamentous material, dense bodies and myelin structures resembling the image of AB in sarcoidosis. Some giant cells containing AB either phagocytosed only few fungi or did not contain any of them. The AB and the fungi did not react with the anti-sporotrichotic antibody, which stained the extracellular AB of sporotrichosis. These two asteroid structures are, therefore, different and unrelated phenomena.
芽生菌病样肉芽肿病是由罗博阿洛博伊菌引起的一种皮肤真菌病。它会引发皮肤肉芽肿，其中的巨细胞吞噬了大量真菌。在一些巨细胞中观察到了胞质内星状体（AB）。其性质尚不清楚，且它们曾被与孢子丝菌病的星状体混淆。我们研究了53例芽生菌病样肉芽肿病患者的84份皮肤活检标本，其中7份进行了电子显微镜（EM）检查。对5份活检标本进行了用多克隆抗申克孢子丝菌抗体的免疫组织化学检测。在HE染色的84份活检标本中，有22份在巨细胞中发现了AB。它们表现为单个嗜酸性胞质结构，周围有一个清晰的空泡。当活检标本用四氧化锇固定时，这个清晰的空泡不出现，因此表明它本质上是脂质，且这个空泡是脂质提取产生的假象。在电子显微镜下，AB由密集的丝状物质束、致密体和类似于结节病中AB图像的髓鞘结构组成。一些含有AB的巨细胞要么只吞噬了很少的真菌，要么没有吞噬任何真菌。AB和真菌与抗孢子丝菌病抗体不发生反应，该抗体可染出孢子丝菌病的细胞外AB。因此，这两种星状体结构是不同且不相关的现象。
