S1852 Retrograde Balloon-Assisted Deep Enteroscopy in the Diagnosis of Metastatic Melanoma

Abstract

INTRODUCTION: A 74 year old male with past medical history of melanoma, presents to clinic due to persistently abnormal small bowel findings on PET-CT scan. The following case illustrates a unique and unusual case of metastatic gastrointestinal disease, and the utility of both capsule endoscopy and balloon-assisted deep enteroscopy to assist in the diagnosis of metastatic melanoma. CASE DESCRIPTION/METHODS: A 74 year old male with past medical history of previously excised melanoma in remission presented to clinic due to persistently abnormal small bowel findings on surveillance PET-CT scan. Patient reported feeling well. Over the last 2 years, multiple PET scans had shown intense focal FDG uptake in distal small bowel, deemed to be inflammatory in nature although melanoma recurrence remained a possibility. Given recurrent findings, patient underwent capsule endoscopy which revealed ulcerated, nodular, and erythematous mucosa likely in distal ileum. Patient underwent retrograde double balloon enteroscopy which showed ulcerated, edematous mucosa in distal ileum at 95 cm from ileocecal valve, with biopsies consistent with metastatic melanoma as confirmed by the presence of melanin in tumor biopsy and positive staining. The site of the lesion was marked with SPOT Tattoo to allow for intraoperative localization. Patient underwent surgical resection which revealed second area of ileal metastasis, which was safely resected. DISCUSSION: The following case illustrates the utility of capsule endoscopy to identify small bowel metastasis; an atypical use in the current practice of capsule endoscopy. This case details how retrograde double balloon enteroscopy, in combination with diagnostic modalities such as PET scans and capsule endoscopy, can assist in the diagnosis of distal small bowel disease including metastasis. This case also illustrates how SPOT tattoo utilization may assist with intraoperative surgical localization of suspicious lesions. While metastatic melanoma in the small intestine is a well-described phenomenon, small bowel metastasis has been detected clinically in only 2%–5% of patients with malignant melanoma. Although these lesions are typically resected surgically for diagnosis, our case illustrates the role of initial small bowel endoscopic imaging to assist in localization to facilitate intraoperative management, and that the combination of capsule endoscopy and retrograde double balloon enteroscopy is a practical and feasible method to evaluate for metastatic disease in the distal small bowel.Figure 1.: Area of ulcerated, nodular, erythematous and congested mucosa seen on Capsule Endoscopy.Figure 2.: Area of ulcerated, nodular, erythematous and congested mucosa seen on Capsule Endoscopy.Figure 3.: Area of ulcerated, erythematous and congested mucosa identified on Retrograde Deep Balloon Enteroscopy.