Pathological lesions of the liver were studied in 14 cases of hairy cell leukemia, a rare hematologic neoplasm involving numerous organs. Tumor infiltration of hepatic parenchyma was observed in all cases. Tumor cells were easily recognized by their cytological features, namely their "halo" appearance consisting of a clear rim of abundant cytoplasm surrounding uniform round or slightly indented nuclei. Portal infiltration was observed in all cases, associated with sinusoidal infiltration in 12 cases. A peculiar change of the sinusoids, i.e., the angiomatous lesions, was noted in 9 of 14 patients. Angiomatous lesions consisted of intralobular cavities without zonal predominance which were lined by tumor cells which replaced the normal sinusoidal wall and were filled with red blood cells and tumor cells. This pattern of involvement is different from hepatic localization of other blood malignancies and is highly suggestive of hairy, cell leukemia. It might reflect the unique phenotype of the tumor cells, which express lymphocytic and monocytic features. The angiomatous lesion strongly mimics peliosis hepatis and could be, as well as in peliosis, the consequence of modification of the sinusoidal barrier. In hairy cell leukemia, sinusoidal wall abnormalities might be secondary to infiltration of the sinusoids by tumor cells.

Crohn’s disease is a systemic disease and sometimes involves the testicle, usually leading to granulomatous lesions. We report herein a case of focal non-granulomatous orchitis in a 21-year-old patient with active Crohn’s disease treated by an anti-tumor necrosis factor monoclonal antibody. This circumscribed testicular lesion mimicked a tumor, leading to orchiectomy. Pre-operative blood tests (i.e. alpha-fetoprotein, lactate dehydrogenase and human chorionic gonadotrophin) were strictly normal Pathological examination of the testicle revealed a focal inflammatory infiltrate predominantly composed of lymphocytes accompanied by few plasma cells, lacking giant cells or granulomas. Importantly, intratubular germ cell neoplasia, atrophy or lithiasis were not observed.After discussing and excluding other plausible causes (burnt-out /regressed germ cell tumor, infection, vascular or traumatic lesions, iatrogenic effects), we concluded that this particular case of orchitis was most likely an extra-digestive manifestation of inflammatory bowel disease. To our knowledge, this is the first described case of focal non-granulomatous orchitis associated with Crohn’s disease.Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2117747284160112