Cutaneous metastasis masquerading an internal malignancy, hilar cholangiocarcinoma – A case report and review of literature

Abstract

Cutaneous metastases can be a masquerade of an internal malignancy and is rare accounting for 0.7-0.9% of cancer patients. Cutaneous metastasis of adenocarcinoma histologic subtype indicates widespread disease and poor prognosis. Herein, we report an exceedingly rare case of cutaneous metastasis, possibly of pancreaticobiliary origin and review of literature on cutaneous metastasis. A 48-year-old woman presented with massive ascites since 4 months. Multiple asymptomatic skin nodules were noted. PET- CT showed extensive ill defined skeletal metastasis and low grade metabolically active ill-defined lesions in the bilateral adnexal region – suspicious for metastatic deposits. Upper gastrointestinal tract (GI) endoscopy and colonoscopy did not reveal any specific lesion. Biopsy from the nodule in the left forearm showed cords, a few vague acinar structures and singly lying cells including a few signet ring cells consistent with poorly differentiated adenocarcinoma with few signet ring cell features. On Immunostaining, the neoplastic cells showed diffuse membranous positivity for Cytokeratin (CK), Cytokeratin 7 (CK 7), CK19 , CDX-2 and negative for TTF-1, CK20, PAX 8 and WT-1. This immunohistochemical profile favours an adenocarcinoma possibly of pancreaticobiliary origin. MR Cholangiopancreaticogram showed ill-defined T2 hypointense diffusion restriction at perihilar region involving the confluence, cystic duct and common hepatic ducts – likely neoplastic etiology (Hilar cholangiocarcinoma – Bismuth – Corlette type II). Palliative chemotherapy and radiotherapy was initiated and the patient is on follow-up. This case emphasis that there should be a strong suspicion of cutaneous metastases in case of any skin nodule with non pinchability of skin especially in old age as it could be the initial presentation of an underlying malignancy and it requires a multidisciplinary approach.