Aortic lesions in aspergillosis: histopathological study of two autopsy cases.

The involvement of the aorta in aspergillosis is relatively rare, and its histopathological features have not been described in detail. In two autopsy cases of invasive aspergillosis in immunologically compromised patients with hematological disorders, the aspergillotic lesions of the aorta showed different characteristic histopathological features depending on the three layers of aortic wall. Intimal lesions were formations of the mural thrombus composed of aggregates of numerous fungal hyphae arranged perpendicularly to the aortic wall. In the media, smooth muscle cells were completely necrotic (anemic infarct of the media), while the framework of elastic fibers was well preserved, with only a few fungal hyphae detected. In the adventitia, an intense, partly granulomatous chronic inflammatory change with fibrosis was observed in association with mycotic embolic occlusion of the vasa vasorum. These histopathological changes were considered to represent one of the typical tissue reaction patterns in the wall of an elastic artery in aspergillosis.

Nuclear pseudoinclusions in angiomyolipoma of the kidney. A case report.

BACKGROUND: Fine needle biopsy has been utilized for the preoperative diagnosis of angiomyolipoma of the kidney. However, the spectrum of diverse nuclear morphology shown by the constituent smooth muscle cells of angiomyolipoma has not been fully elucidated. CASES: An angiomyolipoma was found incidentally in the left kidney of an asymptomatic, 57-year-old woman, and nephrectomy was performed. The tumor was composed predominantly of smooth muscle cells occasionally showing atypical nuclear features. Small aggregates of adipocytes were also found. Direct stamp specimens of the tumor revealed plump, spindle-shaped smooth muscle cells, and the nuclei of many of these cells contained large pseudoinclusions (cytoplasmic invaginations). Histologic review of an additional four cases of renal angiomyolipoma further revealed the frequent occurrence of nuclear pseudoinclusions in smooth muscle cells of the tumor. CONCLUSION: Nuclear pseudoinclusions on fine needle aspiration cytology of renal angiomyolipoma have not received adequate attention. We showed that this finding is a rather common nuclear feature in angiomyolipoma. It is presumably one of the manifestations of nuclear pleomorphism frequently seen in smooth muscle cells of angiomyolipoma and should not be considered an indication of malignancy.