Primary malignant melanoma of the gallbladder in dysplastic naevus syndrome

Abstract

A case of gallbladder involvement by malignant melanoma in a 57-year-old woman is reported. The gallbladder, resected for cholelithiasis, harboured a pedunculated polypoid dark mass, which histologically revealed sheets and nests of epithelioid cells with hyperchromatic nuclei in the lamina propria and at the junctional level. These cells were pigmented (with positive reaction with Schmorl's stain and bleaching with peroxide) and showed immunohistochemical positivity for S-100, gp 100 antigen (HMB-45 antibody) and vimentin. The patient, affected by dysplastic naevus syndrome, had a melanoma in situ excised from the scalp 8 years earlier. The features of the investigated lesion address towards a diagnosis of primary gallbladder melanoma. Furthermore, this is the first time that the existence of such a controversial entity is sustained by the ultrastructural investigation of melanosomes, demonstrating the presence of two melanocitary populations, a typical one exclusively junctional and an atypical one both at the junctional level and in the lamina propria.

Primary biliary tract melanoma: Report of a case and review of the literature

“…12 Ricci and colleagues further confirmed this possibility when they provided ultrastructural evidence of two distinct benign and malignant melanocytic populations in a case of primary melanoma of the gallbladder. 13 The first reported case of primary melanoma of the bile duct was in 1963 by Zaide. 2 The patient was a 47-year-old man with a longstanding history of jaundice.…”

Primary Extracutaneous Malignant Melanoma: A Comprehensive Review with Emphasis on Treatment

“…-The histological examination shows both typical and atypical melanocytes on the edges of the lesions similar to those found in the periphery of primary cutaneous melanomas [8]. Melanomas of the mucous membranes have to be regarded as tumor entities in their own right with respect to the lacking influence of ultraviolet irradiation in pathogenesis, differences in survival periods, in the clinical course of disease, in the pattern of metastases and the response to chemotherapy.…”

“…So far only 11 cases of primary melanoma of the common bile duct and 29 cases of the gall bladder have been reported. The main presenting symptoms were acute cholecystitis, obstructive jaundice, epigastric pain, and melena [8,54]. Surgery is the mainstay of therapy and appears to improve patient outcome.…”

“…Surgery is the mainstay of therapy and appears to improve patient outcome. Commonly performed procedures include Whipple's resection, cholocystectomy, resection of common bile duct and hepatic lobectomy [8,54,55].…”

Primary gallbladder melanoma in dysplastic nevus syndrome: Report of case and literature review

“…The most conflicting area is the histogenesis of this primary entity or its possibility. Ricci and coworkers (28) showed melanocytes, both normal and malignant, in their case of malignant melanoma of the gallbladder.…”