Surachai Amornsawadwattana, MD1, Elizabeth Huebner, MD2
1Washington University School of Medicine, Saint Louis, MO; 2Washington University School of Medicine, St. Louis, MO
Introduction: It is believed that patients with Celiac disease (CD) are at increased risk of certain malignancies. However, CD patients are not associated with cutaneous malignant melanoma and thus additional screening is not indicated. We report an unusual case of a patient with first diagnoses of simultaneous CD and isolated small intestinal melanoma.
Case Description/Methods: A 55-year-old female without history of malignant melanoma (MM) presented with chronic diarrhea. Physical exam and laboratory results were unremarkable except a tissue transglutaminase IgA antibody was elevated at 126.4 units (normal 0.00-19.99.). An esophagogastroduodenoscopy was performed and demonstrated scalloping of the duodenal folds. A hyperpigmented mass was incidentally found in the proximal jejunum (Figure). Duodenal biopsies showed villous blunting, chronic inflammation and increased intraepithelial lymphocytes, which was consistent with CD. Biopsies of the jejunal mass revealed a densely pigmented nodule of atypical cells with large hyperchromatic nuclei, abundant cytoplasm, and mitoses. An immunohistochemical stain was positive for Melan-A and S100, which confirmed a diagnosis of MM of the small bowel.
Additional imaging revealed no signs of metastatic disease. Subsequently, the patient underwent laparoscopic resection of the small bowel mass and the pathology showed malignant MM with negative margins. Then, she was started on Trametinib and Dabrafenib for about 5 months, but was discontinued due to side effects. Currently, the patient remains disease-free 36 months after surgery. Diarrhea is also much improved after starting a gluten free diet.
Discussion: Small bowel malignancies are rare, accounting for 3% of GI neoplasms and the majority of small bowel neoplasms represent metastatic disease. The small intestine is also considered the most common site of melanoma metastases to the GI tract. Primary small intestinal MM is characterized by MM of the small bowel without evidence of a primary extra-intestinal lesion. Whether this represents a true primary malignancy or a metastatic disease from an unrecognized or a regressed lesion elsewhere remains debatable. The main treatment of primary small intestinal melanoma is surgical resection.
Although patients with CD in general have increased risk of malignancy, there is no known association between CD and MM. This case highlights a rare incidental primary small intestinal melanoma in the setting of a patient who is symptomatic from CD.
Citation: Surachai Amornsawadwattana, MD; Elizabeth Huebner, MD. P2617 - INCIDENTAL ISOLATED SMALL INTESTINAL MELANOMA IN A PATIENT WITH NEWLY DIAGNOSED CELIAC DISEASE. Program No. P2617. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.