Melanoma is a highly malignant neoplasm with the most typical primary locations in the skin and eyeball and rarely reported in the other organs, including the gallbladder. More commonly metastases of melanoma of various primary sites to the gallbladder are observed. However, generally melanoma of the gallbladder is a rare entity with only 217 cases reported in the literature up to date. The paper summarizes knowledge on epidemiology, symptoms, laboratory and imaging findings, morphology, treatment options, and outcome of patients with both primary and metastatic melanoma to the gallbladder.

Malakoplakia is regarded as a chronic granulomatous infl ammatory disease with a good prognosis. It usually aff ects the urinary system, especially the urinary bladder. Bacterial infections, including E. coli are thought to be the main factor in pathogenesis. It frequently coexists with chronic diseases and immunosuppression state. Histopathological examination of aff ected tissue samples is thought to be the best diagnostic method. Th e basic microscopic feature is mixed infl ammatory infi ltration containing foamy histiocytes known as von Hansemann cells, frequently with basophilic inclusions known as Michaelis-Gutmann bodies. Symptoms and the clinical course of malakoplakia depend on location and the extent of the lesions. Th e lesion is treated successfully with antibiotic therapy and surgical excision.