H Liu, J Wang, C Bewtra, D Sarma
melanoma, metastatic melanoma, metastatic melanoma of gallbladder
H Liu, J Wang, C Bewtra, D Sarma. Symptomatic Gallbladder Metastasis From Cutaneous Melanoma. The Internet Journal of Gastroenterology. 2008 Volume 7 Number 2.
Although 50%-65% of metastatic gallbladder tumors come form malignant melanoma, clinically diagnosed cases are very rare. We are reporting such a symptomatic case of metastatic melanoma in the gall bladder occurring in a 40-year-old man.
A 40-year-old male presented with right upper quadrant abdominal pain for 3 weeks. A CT scan was obtained, which demonstrated a distended gallbladder. It also showed widespread metastatic lesions in the lung, liver, and bone (10 th rib) and peripancreatic and porta hepatis adenopathy. Five years earlier, a malignant melanoma (stage IV) was resected from his left flank. The tumor was ulcerated and measured 16 mm in maximum depth. Metastatic melanoma was present in left axillary lymph nodes. The patient had multiple local recurrences and re-excisions. He had also been treated with chemotherapeutic agent Taxol. An exploratory laparotomy and cholecystectomy showed a markedly enlarged gallbladder with multiple intramural metastatic melanoma nodules measuring up to 2.0 cm (Figure 1).
The patient had an uneventful post-operative course and was discharged from the hospital to be followed by the oncologist.
Review of English literature reveals a total of 54 cases (1) since 1955 when the first one was reported. Cutaneous melanoma is notorious for its potential to recur and metastasize to any organs. Important predictors for local recurrence include tumor thickness and ulceration. Distant metastasis occurs through lymphatic as well as hematogenous routes. The majority of patients with local recurrence will develop systemic metastasis (2).
Melanoma seems to have special propensity to spread to gastrointestinal tract. Up to 58% of melanoma cases show intestinal metastasis at autopsy compared to 20% of non- melanoma malignancies (2, 3). Fifteen per cent of patients dying of metastatic melanoma were found to have metastatic tumor of the gallbladder. The patients with symptomatic gallbladder metastasis survived longer than the ones without symptoms (4). Metastasis to gallbladder is usually a component of extensive spread, and thus carries a poor prognosis, especially in asymptomatic patients.
Histological diagnosis of metastatic melanoma is usually straightforward showing a high-grade malignancy often with extensive areas of necrosis. However, the distinction of metastatic melanoma from a primary lesion is problematic, especially in patient with regression of primary lesion. Melanocytes are derived from the neural crest cells during the early development and exist in the biliary system. Primary melanoma of the gallbladder is biologically plausible but is a very rare event (5). History of cutaneous melanoma and multiple local recurrences, together with multiple metastases in other sites is consistent with metastatic nature of the gallbladder tumor in our patient.
Deba P Sarma, MD Department of Pathology Creighton University Medical Center Omaha, NE 68131, USA E-mail: email@example.com