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Reference
Respiratory Tract
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Sclerosing "hemangioma" (pneumocytoma)
(Diagnostic Histopathology of Tumors. Fletcher CDM, Churchill-Livingstone 2 nd Ed)
Sclerosing hemangioma is a rare benign lung neoplasm that was first described by Liebow & Hubbell in 1956.
The tumor shows a marked female predilection and is more common in the fourth to fifth decades of life. In most cases, the tumor is discovered incidentally on a routine chest X-ray, but in some cases patients may present with chest pain. Grossly, these tumors present as relatively small (< 5 cm in diameter), well-circumscribed intraparenchymal masses unrelated to bronchial structures, with a finely granular cut surface.
Sclerosing hemangioma is characterized histologically by a variety of growth patterns, including papillary, solid, angiomatous, and sclerotic. Rare examples have been described showing a prominent granulomatous reaction as well as a cystic appearance. The neoplastic cell population is characterized by a monotonous proliferation of round to polygonal, bland-appearing tumor cells with central nuclei without nucleoli, and abundant clear or lightly eosinophilic cytoplasm. In the papillary areas, the surface of the papillae will be composed of a single cell layer of smaller, darker cuboidal cells with large, hyperchromatic and immatureappearing nuclei. In the more solid areas, the tumor cells can be admixed with foamy macrophages and often contain entrapped alveolar structures. The more angiomatous areas may resemble capillary or cavernous hemangioma; perivascular hyalinization with deposition of abundant collagenous matrix results in the characteristic "sclerosing" appearance. Necrosis, hemorrhage and mitotic activity are not features seen in these tumors.
The more recent ultrastructural and immunohistochemical studies indicate that the tumor cells are epithelial and most closely correspond to alveolar pneumocytes. Immunohistochemical stains for surfactant apoprotein have been strongly positive in the tumor cells in most, but not all studies. Other markers that consistently label these tumors include EMA and vimentin. Stains for keratin intermediate filaments have been claimed to be positive by some, but such results have not been reproduced by others. Most recently, an immunohistochemical study also showed positive results with neuroendocrine markers.
Sclerosing hemangiomas are benign tumors. Complete surgical excision of the lesion appears to be the treatment of choice and is curative. There is one reported case, however, of a metastatic deposit in a lymph node in a case of sclerosing hemangioma of the lung.
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So-called sclerosing hemangioma
(in Surgical Pathology. Rosai-Ackermann's. Elsevier-Mosby)
Sclerosing hemangioma is a distinctive lesion that occurs mostly in adult females, being generally detected as an asymptomatic small, solitary nodule on the chest x-ray film. On serial films, the lesion is found to be stable or, at the most, very slow-growing. Grossly, it is well circumscribed but not encapsulated, solid, and tan or yellow, sometimes with hemorrhagic areas. Occasionally it may be cystic.
Microscopically, there is a compact growth of polygonal cells with relatively abundant eosinophilic cytoplasm, arranged in a solid as well as a papillary or sclerotic pattern; this growth may be continuous with that of identifiable bronchiolar epithelium. Foci of fresh and old hemorrhage are frequent, and aggregates of xanthoma cells may be present. Exceptionally, there is an accompanying florid granulomatous reaction. The histogenesis of this lesion has been highly controversial since its description as an entity, which has been variously proposed to be of endothelial, histiocytic, mesothelial and epithelial nature.
Immunohistochemically, there are two distinct components. One is of clearly epithelial nature and reactive for EMA, keratin, CD15, Ber-EP4, apocrine epithelial antigen, and surfactant apoprotein. Some of these reactivities correspond to those of type 11 (granular) pneumocytes, as supported by the ultrastructural finding of a microvillous-like folding of the cell membrane and lamellar inclusion. The second and numerically more prominent component (referred to as round or stromal cells) is negative for most of these markers except EMA. However, it is immunoreactive for TTF1, a feature which it shares with the first component and that suggests an origin from primitive respiratory epithelium. The proposal has been made by some authors to give this tumor the name of papillary or sclerosing pneumocytoma, but since it is not yet clear whether the granular pneumocytic component is neoplastic or not, this change in terminology may be a little premature.
From a clinical standpoint, sclerosing hemangioma is a generally benign lesion cured by conservative surgery, although a few malignant examples that have metastasized to the regional nodes are on record.
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Histopathology. 2002 Mar;40(3):291-3
Sclerosing haemangioma of the lung is positive for MIB-1 in cell membrane and cytoplasmic staining pattern.
Hattori H.
Department of Pathology, Kariya General Hospital, Kariya, Aichi, Japan. hattori.kariya-gh.pathol@kariya-gh.ne.jp
AIMS: MIB-1 is a monoclonal antibody raised against the recombinant part of the Ki67 antigen, which is expressed in the nuclei of all the active part of the cell cycle. Recently, cell membrane and cytoplasmic pattern of staining with MIB-1 in hyalinizing trabecular adenoma of the thyroid was reported. Sclerosing haemangioma of the lung is a tumour of uncertain histogenesis with a usually benign course. The tumour is mainly composed of cuboidal cells that line the papillary or tubular structure and pale cells that are found in the stroma. METHODS AND RESULTS: We examined a cell membrane and cytoplasmic immunoreactive pattern for MIB-1 antibody in sclerosing haemangioma. In all of the five cases examined, distinct cell membrane and cytoplasmic MIB-1 positivity mainly in the pale cells was noted. None of the carcinomas of the lung showed this type of staining with MIB-1. CONCLUSION: This result shows that, although the staining may be a result of cross reaction, cell membrane and cytoplasmic MIB-1 positivity is unique in that it could distinguish sclerosing haemangioma from other malignant epithelial tumours of the lung.
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