Primary biliary tract malignant melanoma: US, CT, and MR findings

Perivascular epithelioid cell tumor (PEComa) of the cystic duct

Perivascular epithelioid cell tumors, also known as PEComas, are rare mesenchymal tumors composed mainly of epithelioid cells found in perivascular tissue. PEComas occur most frequently in the kidney, uterus, the gastrointestinal tract, liver, and retroperitoneum; those originating in the biliary tree are extremely rare. We report a case of benign PEComa of the cystic duct with positive TFE3 staining on immunohistochemistry.A 66-year-old woman was referred for a 20 mm mass adjacent to the common bile duct discovered incidentally on abdominal ultrasound. Laboratory data including tumor markers were unremarkable. The tumor appeared to arise from the cystic duct, showed early enhancement, and compressed the common bile duct on imaging studies. Endoscopic ultrasound-guided fine-needle aspiration revealed round- and spindle-shaped atypical cells with eosinophilic cytoplasm and brown deposits suggestive of melanin granules. Histological examination of the resected specimen revealed a tumor consisting of epithelioid cells forming an alveolar structure, with melanin pigmentation. Immunohistochemistry was positive for HMB-45 and TFE3, consistent with benign pigmented PEComa of the cystic duct. Melanotic, myogenic, and TFE3 staining are helpful when diagnosing PEComas arising in unusual locations.

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Uncommon neoplasms of the biliary tract: radiological findings

OBJECTIVE

To report our cancer centre experience in the biliary tumours incidence other than cholangiocellular-carcinoma, emphasizing the radiological features.

METHODS

197 patients with biliary disease undergoing Gd-EOB-DTPA-enhanced MRI were reviewed. Four radiologists evaluated retrospectively size, structure, anatomical site and signal intensity of lesions on MRI. Enhancement-pattern during the arterial-, portal- and late-phase on ultrasound, CT and MR study was assessed as well as the enhancement pattern during the hepatobiliary-phase on MRI.

RESULTS

23 patients were selected. The lesion was intraductal in 5 cases, periductal in 14 and intrahepatic in 4. 16 lesions were solid, 5 uniloculated cystic and 2 complex cystic. In five patients the lesion was simple cyst, with a signal intensity in T₁ weighted (T1W) and T₂ weighted (T2W) similar to the gallbladder. In two patients with complex cystic lesion, the solid component was heterogeneously hypointense in T₁ W, hyperintense in T₂ W with a restricted diffusion. The solid component showed heterogeneous contrast-enhancement on CT, MR and ultrasound. The tumour was intrahepatic in two patients, with signal hypointense in T₁ W and hyperintense in T₂ W. Diffusion was restricted. The lesions showed heterogeneous contrast-enhancement. The periductal lesions were hypointense in T₁ W, hyperintense in T₂ W with restricted diffusion. The lesion showed progressive contrast-enhancement. Peribiliary melanoma was hyperintense in T₁ W, hyperintense in T₂ W with restricted diffusion and progressively contrast-enhanced.

CONCLUSION

Biliary tumours can have a wide spectrum of radiologic appearances and consequently represent a diagnostic challenge for the radiologist. Advances in knowledge: MRI is the technique of choice in diagnosing biliary tumours, including rare (non-CCC) tumours.

Primary Bile Duct Melanoma Causing Obstructive Jaundice. ACG Case Rep J. 2016;3:e128. [PMID: 27807580 PMCID: PMC5062673 DOI: 10.14309/crj.2016.101]

Malignant melanoma is one of the few malignancies that are well known for unusual behavior. Primary malignant melanoma usually originates from squamous epithelium of skin, mucous membranes, retina, and uvea. Although melanoma can metastasize to any part of the body, including biliary tract, primary malignant melanoma of bile ducts is an extremely rare entity. We present a 52-year-old man who presented with 5-month epigastric pain and 15-pound weight loss, with 1-week duration of jaundice, nausea/vomiting, pale stools, and dark urine, blood work suggested cholestatic jaundice. Imaging revealed a large perihilar/peripancreatic mass involving the portal vein and hepatic artery, and intrahepatic biliary dilation. Biliary brushings revealed neoplastic cells strongly suggestive of malignant melanoma.

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

INTRODUCTION

Primary melanoma of the bile duct is extremely rare with only nine cases of primary melanoma of the bile duct reported in the literature.

PRESENTATION OF CASE

A 55-year-old previously healthy gentleman developed increasing jaundice over several months and subsequently underwent an ERCP with stone extraction. Cytology brushings in an area of a distal stricture in the bile duct were concerning for cholangiocarcinoma. The patient was referred to our institution and underwent a pancreaticoduodenectomy. The surgical specimen showed a single 4.5cm polypoid lesion located in the bile duct. A diagnosis of melanoma was rendered after immunohistochemical studies on the tumor demonstrated positivity for melanoma markers. Follow-up of the patient with skin, ocular, and lymph node exams showed no evidence of melanoma. A PET scan 4 and 10 months post-surgery failed to reveal either a primary skin lesion or other sites of metastases.

DISCUSSION

The vast majority of melanomas of the bile duct represent metastases from a cutaneous source and tend to present as multiple flat pigmented lesions. Conversely, cases of primary bile duct melanoma are characterized by a distinct gross morphology consisting of a solitary intraluminal polypoid lesion attached by a pedicle with no other identifiable primary lesion. Other supporting criteria include absence of other involved sites and presence of an in situ junctional component.

CONCLUSION

Given the clinical history, gross findings, and lack of a primary cutaneous site or other demonstrable metastases, this patient likely represents the tenth reported case of primary biliary tract melanoma.

Mimics of cholangiocarcinoma: spectrum of disease

Cholangiocarcinoma is the second most common primary malignant hepatobiliary neoplasm, accounting for approximately 15% of liver cancers. Diagnosis of cholangiocarcinoma is challenging and the prognosis is uniformly poor, with recurrence rates of 60%-90% after surgical resection. A wide spectrum of neoplastic and nonneoplastic conditions of the biliary tract may masquerade as cholangiocarcinoma, adding to the complexity of management in patients suspected to have cholangiocarcinoma. Mimics of cholangiocarcinoma constitute a heterogeneous group of entities that includes primary sclerosing cholangitis, recurrent pyogenic cholangitis, acquired immunodeficiency syndrome cholangiopathy, autoimmune pancreatitis, inflammatory pseudotumor, Mirizzi syndrome, xanthogranulomatous cholangitis, sarcoidosis, chemotherapy-induced sclerosis, hepatocellular carcinoma, metastases, melanoma, lymphoma, leukemia, and carcinoid tumors. These entities demonstrate characteristic histomorphology and variable clinicobiologic behaviors. The imaging findings of these disparate entities are protean and may be indistinguishable from those of cholangiocarcinoma. In most cases, a definitive diagnosis can be established only with histopathologic examination of a biopsy specimen.

Malignant melanoma of the gallbladder: a report of two cases and review of the literature

Melanoma metastatic to the gallbladder is rare. When present, it is often part of a widespread complex of metastases. Primary gallbladder melanomas are also extremely rare and can sometimes be difficult to distinguish from metastatic lesions. The optimal treatment for malignant melanoma of the gallbladder remains unclear, and prognosis is generally poor. We present here two cases of patients with metastatic lesions to the gallbladder. One patient presented with symptomatic cholelithiasis and was found incidentally to have a metastasis. Another patient had known a metastasis, but underwent curative resection of the only site of disease. We review the published literature for gallbladder melanoma, both primary and metastatic to determine the role of surgery in this disease.

Metastatic melanoma of the gallbladder

We report the findings of a magnetic resonance (MR) imaging analysis of metastatic melanoma of the gallbladder in a 36-year-old woman. MR imaging revealed that the gallbladder wall was diffusely thickened, and the tumor showed slightly high-intensity on T1-weighted images. The apparent diffusion coefficient value of the tumor was 0.69 x 10(-3)mm(2)/s, indicating high cellularity. Surgical specimens revealed that the tumor was a metastatic melanoma showing medullary growth with intratumoral hemorrhaging. These MR findings are helpful for preoperative diagnosis.

Primary malignant melanoma of the common bile duct: a case report and literature review

Primary malignant melanoma of the common bile duct is rare. Only seven cases have been described in the literature. Diagnosis is based on failure to find another primary site, histological examination with electron microscopy, and immunohistochemical tests. We describe a new case of primary malignant melanoma of the biliary tract and present a review of previous reports.