An unusual case of chronic diarrhea: a case report

Excerpt

Gastroenteropancreatic-neuroendocrine neoplasms or tumors (GEP-NEN or NETs) are rare tumors arising from the diffuse neuroendocrine system. Their annual incidence is less than 5 cases per 100,000 inhabitants [1]. NETs are classified as non-functional or functional tumors. The latter have a better prognosis and are associated with hormonal syndromes. NETs’ clinical presentation can be characterized by non-specific symptoms, such as diarrhea, weight loss, hypoglycemia, rectal bleeding, and also by flushing and wheezing/asthma-like symptoms when Carcinoid Syndrome is the underlying cause of symptoms. Manifestations of non-functional tumors are mainly related to compression of neighboring anatomical structures [2, 3]. Because of their non-specific symptoms, NETs are often misdiagnosed. This case report describes a nuanced and very insidious clinical presentation of Atypical Carcinoid Syndrome due to a GEP-NEN, characterized by chronic diarrhea as primary symptom. Although several cases of diarrhea due to GEP-NENs are reported in the literature [4], this case underlines how a simple clinical symptom may hide a complex diagnosis. This clinical case highlights the complexity of the diagnostic process and the difficulties in interpreting the examinations for this type of tumor, showing how the negativity of first-level examinations did not prevent from performing further investigations, in the presence of a suggestive clinical presentation. The search of similar cases in the published literature suggests that this represents an unusual presentation of a NET. …