Aurora B kinase in Hodgkin lymphoma: immunohistochemical pattern of expression in neoplastic Hodgkin and Reed-Sternberg cells.

Aurora B is a member of the chromosomal passenger complex, which is essential for proper completion of mitosis and cell division (cytokinesis). Inappropriate chromosomal segregation and cytokinesis due to deregulated expression of chromosome passenger proteins may lead to aneuploidy and cancer including lymphomas. According to our knowledge there are extremely limited studies investigating the immunohistochemical expression of Aurora B in tumor specimens of Hodgkin lymphoma. Our purpose was to characterize the expression of Aurora B in biopsies of Hodgkin lymphomas, and to evaluate the pattern of immunoreactivity in neoplastic Hodgkin and Reed-Sternberg cells (RS cells). We examined Aurora B immunoreactivity in paraffin sections of 15 samples of Hodgkin lymphomas, obtained from 15 patients, 8 men and 7 women. Ten were of nodular sclerosis type and five were of mixed cellularity. Our results showed immunoexpression of Aurora B in mononuclear lymphoid cells as well as in bi- and multinucleated RS cells. In addition, positive neoplastic cells in mitosis were observed, whereas a subpopulation without evidence of immunoreaction was also detected in each case. Taken together our results point to a possible association between Aurora B expression and mitotic deregulation in Hodgkin lymphoma, which may provide novel targets for treatment.

Malakoplakia of the colon associated with colonic adenocarcinoma diagnosed in colonic biopsies.

Malakoplakia, typically involving the urinary tract, is an uncommon form of chronic inflammation caused by chronic infections and characterized by accumulation of macrophages. It has also been found in many other sites such as the gastrointestinal tract, pancreas, liver, lymph nodes, skin, respiratory tract, adrenal gland, vagina and brain. We present a case of a 64-year-old man referred to our hospital with cachexia and radiologic evidence of metastatic tumor of the liver. Colonoscopy revealed a large malignant - appearing polypoid mass of the ascending colon and multiple distinct polyps throughout the rest of the colon. Biopsies of the ascending colon mass confirmed the diagnosis of adenocarcinoma. Histological examination of two of the other polyps revealed malakoplakia which was characterized by aggregates of granular histiocytes with Michaelis - Gutmann bodies and histochemically confirmed with periodic acid-Schiff and von Kossa stains. This is a rare case diagnosed on endoscopic samples. The majority of reported cases were found in surgical specimens. In addition, the endoscopic appearance of multiple polyps is unusual in malakoplakia.