Programmed Cell Death-Ligand 1 (PD-L1) Expression in Anal Cancer.

OBJECTIVE: To evaluate the expression of programmed cell death-ligand 1 (PD-L1) in anal cancer. PATIENTS AND METHODS: In a retrospective cohort analysis, subjects with squamous cell carcinoma of the anal canal were tested for PD-L1 expression, then followed for recurrence and survival. Crude recurrence rates (CRRs), crude mortality rates (CMRs), and crude event rates (CERs) were assessed for PD-L1-dependent differences using Poisson regression. All 3 types of crude rate were expressed as the number that occurred per hundred person-years (hPY) of follow-up. RESULTS: Samples from 41 subjects were evaluated for PD-L1 expression; 23 (56%) were positive. Subjects with PD-L1-expressing versus PD-L1-negative tumors respectively had CRRs of 30.8 versus 12.1 recurrences/hPY (P=0.082), CMRs of 16.7 versus 12.0 deaths/hPY (P=0.47), and CERs of 39.2 versus 16.9 events/hPY (P=0.069). CONCLUSIONS: PD-L1 positivity was associated with worse CRR and CER, and marginally worse CMR. The effect on progression-free and overall survival needs to be validated in a study with a larger sample size.

Primary Bile Duct Melanoma Causing Obstructive Jaundice.

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.