Indiana University Indianapolis, IN, United States
Shahd Duzdar, MD1, Mark Gromski, MD2 1Indiana University, Indianapolis, IN; 2Indiana University School of Medicine, Indianapolis, IN
Introduction: Squamous cell carcinoma (SCC) of the anus is a rare form of gastrointestinal cancer, accounting for about 2.7% of GI cancers in the United States1. Metastasis from anal SCC most commonly involves locoregional spread, followed by metastasis to liver and bone1. We introduce a rare case of metastatic squamous cell anal cancer that presented as a solitary pancreatic lesion.
Case Description/Methods: A 66 year-old woman with a history of type 2 diabetes and chronic diarrhea for over a year presented with dizziness and syncope. Syncope was initially thought to be secondary to orthostatic hypotension. Further workup with CT scan showed a 6.6 x 3.2 cm mass in the pancreatic body with portal vein compression as well as an indeterminate wall thickening of the anus. Labs were significant for a hemoglobin of 10.2 g/dL (from 11.9 a year prior), CA 19-9 of 1,747 U/ml (normal < 37) and CEA of 3.2 ng/mL (normal < 2.5). Further chart review showed that she had a history of a positive fecal immunochemical test 4 months prior, for which she had refused colonoscopy.
As a next step in her diagnostic work-up, endoscopic ultrasound (EUS) with fine needle biopsy (FNB) was pursued. On EUS, patient was found to have a round hypoechoic mass involving the head and genu of the pancreas, with invasion into the portal vein and upstream pancreatic duct dilation. Pathology from FNB showed anal SCC. A flexible sigmoidoscopy was also performed at the same time, showing a 4cm fungating mass in the anal canal. Biopsy of the anal mass was positive for high grade anal SCC. Oncology was consulted and eventually the decision was made to pursue hospice care.
The usual presentation of anal SCC includes bleeding, constipation, tenesmus or diarrhea2. At initial presentation, only 10-15% of patients present with distant metastases2. The most common first metastatic site is the liver, followed by non-regional lymph nodes, bone, kidney and peritoneum1. To our knowledge, there have been no cases of solitary metastasis to the pancreas with squamous cell anal cancer. Metastatic disease, including SCC, needs to be in the differential diagnosis for a solitary pancreas mass, particularly if the patient presents with other concomitant symptoms such as ours (diarrhea, anemia).
1. Nilsson, M. P et al. (2020). Patterns of recurrence in anal cancer: A detailed analysis. Radiation Oncology, 15(1)
2. Russo, S. et al. Critical Review Executive Summary of the American Radium Society Appropriate Use Criteria for Treatment of Anal Cancer.
Figure: Figure A: Solitary Pancreatic Mass Figure B: Evidence of portal vein (PV) compression by pancreatic mass Figure C: Endoscopic image of rectal mass
Disclosures: Shahd Duzdar indicated no relevant financial relationships. Mark Gromski indicated no relevant financial relationships.
Shahd Duzdar, MD1, Mark Gromski, MD2. P2199 - An Unusual Pancreatic Mass: Metastatic Squamous Cell Carcinoma of the Anus Presenting as Solitary Pancreatic Lesion, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.