Penicillium marneffei is an intracellular opportunistic fungus causing invasive mycosis in AIDS patients. T cells and macrophages are important for protection in vivo. However, the role of T-cell cytokines in the immune response against P. marneffei is still unknown. We studied by semiquantitative reverse transcription-PCR and biological assays the patterns of expression of Th1 and Th2 cytokines in the organs of wild-type (wt) and gamma interferon (IFN-␥) knockout (GKO) mice infected intravenously with P. marneffei conidia. At 3 ؋ 10 5 conidia/mouse, a self-limiting infection developed in wt BALB/c mice, whereas all GKO mice died at day 18 postinoculation. Splenic and hepatic granulomas were present in wt mice, whereas disorganized masses of macrophages and yeast cells were detected in GKO mice. The infection resolved faster in the spleens than in the livers of wt mice and was associated with the local expression of type 1 cytokines (high levels of interleukin-12 [IL-12] and IFN-␥) but not type 2 cytokines (low levels of IL-4 and IL-10). Conversely, both type 1 and type 2 cytokines were detected in the livers of wt animals. Disregulation of the cytokine profile was seen in the spleens but not in the livers of GKO mice. The inducible nitric oxide synthase mRNA level was low and the TNF-␣ level was high in both spleens and livers of GKO mice compared to wt mice. These data suggest that the polarization of a protective type 1 immune response against P. marneffei is regulated at the level of individual organs and that the absence of IFN-␥ is crucial for the activation of fungicidal macrophages and the development of granulomas.

HighlightsAppendiceal diverticulitis is often overlooked with high risk of perforation.Appendiceal diverticula is often associated to appendiceal neoplasm.Accurate appendectomy should be performed in order to permit appropriate pathological examination.Prophylactic appendectomy should be performed in asymptomatic patients with appendiceal.

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We report two cases of autopsy confirmed angiosarcoma in adult males, presenting as diffuse pleuropulmonary tumours and simulating malignant mesothelioma. Both the lesions grew along the serosal surfaces and were characterized by variably thick rinds of tissue encasing the lung. The pulmonary parenchyma showed diffuse, dark red, subpleural consolidations and multiple cavitations. Histologically, the lesions were composed by atypical spindle and polygonal, epithelioid cells showing rudimentary vascular differentiation and exhibiting strong positivity for factor VIII, CD31, CD34 and vimentin, We conclude that angiosarcoma may present with preponderant or exclusive involvement of pleura and peripheral lung and that it should be added to the list of tumours capable of simulating malignant mesothelioma.

The authors report 2 cases of an apparently unpublished stromal tumor of the lung characterized by a predominantly endobronchial growth pattern and benign-appearing clear cells. Both tumors were discovered incidentally in adult patients during routine workups for other medical reasons and treated with lobectomy. On gross inspection there was no evidence of infiltration of the adjacent lung tissue. Microscopically, both lesions featured monotonous oval-shaped to spindle-shaped cells growing in a vaguely nested pattern. The cytoplasm was slightly vacuolated or granular. In 1 case there was a variable admixture with mature fat. Immunohistochemistry was negative for markers of epithelial and stromal differentiation except for vimentin. A focal reaction for CD34 was seen in 1 case. No mutation of coding sequence of VHL gene was seen in one case. Medical follow-up at 1 year was negative for tumor recurrence or metastases. The broad differential diagnosis within the spectrum of stromal lung tumor is discussed. Owing to distinctive microscopic features such as the nesting of clear cells within a vascularized background, both tumors appeared similar to hemangioblastoma, although the expected immunohistochemical profile of the latter was not fully expressed. Because of pattern of growth seen in both lesions we believe that the appellation of endobronchial, hemangioblastoma-like clear cell stromal tumor may be provisionally designed.

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