Sclerosing Hemangioma: A Case With Neuroendocrine Differentiation

The sclerosing hemangioma is a rare benign tumor whose histogenesis continues to be controversial. Since the initial description by Liebow and Hubbell in 1956, theories on the cell of origin have included endothelial, alveolar pneumocyte, mesothelial, and epithelial. The tumor is generally solitary, with a female predominance. The patient, a 51-year-old woman, presented with a left hilar mass, grossly, a solid 3 to 4 cm nodule. Histologically, classic features of sclerosing hemangioma were found with solid areas composed of polygonal cells. Also noted were foamy histiocytes and regions of dense sclerosis. Immunohistochemical studies were performed. High and low molecular weight cytokeratin and carcinoembryonic antigen were nonconclusive. Ultrastructural analysis revealed tumor cells that were uniform with few cytoplasmic organelles and cell membranes closely interlocked that were connected by small adhering-type junctions. Thus, the cells were not found to be typically epithelial, endothelial, nor mesothelial; however, a few intracytoplasmic dense core granules were noted, suggesting neuroendocrine origin. Subsequent immunostaining for neuron specific enolase was positive. Vasoactive intestinal peptide, substance P, calcitonin gene related peptide, and bombesin were detected in the cytoplasm of different cell populations with varying intensities, which supported the ultrastructural analysis findings of neuroendocrine features. The findings suggest that sclerosing hemangioma may be of neuroendocrine origin and is capable of producing a number of bioactive peptides.