Context and objectives: We were referred a patient with metastatic well differentiated endocrine tumor of the small intestine (mid-gut carcinoid) in whom asymptomatic subcutaneous gluteal nodules had been identified on routine abdominal CT, and labeled as metastases. This prompted us to assess the prevalence and cause of these nodules.

Design: Retrospective, cross-sectional.

Setting: University Teaching Hospital.

Methods: Routine abdominal CT scans of 56 patients with metastatic mid-gut carcinoid were analyzed by two independent radiologists, blinded to treatment status (depot somatostatin analogs).

Main Outcome Measures: Number of patients with nodules; number of injections, duration and total cumulative dose per patient.

Results: No nodules were detected in 13 patients not on depot somatostatin therapy. Nodules were found in 29/43(67%) patients on somatostatin analog therapy: 16/22 patients on Lanreotide Autogel; 5/12 patients on Somatostatin LAR only; and 8/9 patients who had been treated with both somatostatin analogs. There was no difference in the clinical state of those with or without nodules. Per patient the average number was 7, and average size 1 cm. Presence of nodules was significantly associated with total number of injections (P = 0.024), duration on treatment (P = 0.022) and cumulative dose of Lanreotide Autogel (P < 0.001). Nodules underwent involution on follow-up imaging.

Conclusion: Patients with metastatic mid-gut carcinoid tumors have large numbers of asymptomatic subcutaneous nodules in the gluteal area when on either depot somatostatin analog, but these resolve over time. This clear observation gives reassurance to patients and those managing them that such nodules are unlikely to represent metastases.