Synchronous Neoplasms of the Small Bowel: A Diagnostic Challenge

Small bowel tumours are rare, representing about 0.5% of all tumours and about 3% of gastrointestinal tract tumours. The low prevalence contrasts with the vast surface area of the small intestine, which accounts for over 90% of the surface area of the digestive tract. The frequency of small tumours decreases from proximal to distal, and therefore from the duodenum to the ileum. The histological types differ in terms of prevalence according to the affected segment, with adenocarcinoma being the most frequent in the duodenum and jejunum and carcinoid tumour in the ileum. Diagnosis is challenging due to clinical non-specificity, low prevalence and a low level of suspicion. Schwannomas are typically benign tumours that arise from Schwann's cells and are rarely found in the small intestine. It is even more rare to find them together with another histological type, namely adenocarcinoma. No cases have been reported in the literature of these lesions occurring in the small intestine simultaneously. Further studies are needed to clarify the underlying pathophysiology of these synchronous tumours. The authors present the case of an 86-year-old female patient admitted for high intestinal subocclusion, with refractory vomiting and involuntary weight loss. Two synchronous lesions in the digestive tract were identified: an adenocarcinoma in the duodenum and a schwannoma in the ileum. The patient underwent surgical resection of both lesions. A high level of suspicion combined with a multidisciplinary approach is necessary for timely diagnosis and surgical resolution.

Small bowel neoplasms are rare and clinically non-specific; in addition, diagnosis is difficult due to imaging artifacts and tumour inaccessibility for biopsy for definitive histological diagnosis.Gastrointestinal schwannomas are rare and the pathophysiology of synchrony with other histological subtypes remains to be clarified.A multidisciplinary approach from the beginning is important for a timely diagnosis and better outcome.