Possible role of TGF β1 in inflammatory pseudotumor associated with multiple neuroendocrine tumors of the small intestine

IntroductionInflammatory myofibroblastic tumors (IMTs), a rare condition of unknown etiology, have often been reported to be associated with specific infections or malignant tumors. The question of whether IMT themselves are an inflammatory or a neoplastic process is still going on.Case reportA 57-year-old female patient was transferred to our hospital with ileus caused by a mesenterial tumor. Intraoperatively, the mesenteric mass and the dependent small intestine segment, as well as a suspect hepatic lesion, were resected. The histopathological investigation revealed 8 malignant neuroendocrine tumors (NET) of the small intestine with lymphatic and hepatic metastasis and a mesenteric IMT. The postoperative course was uneventful, and the patient was discharged on the 18th postoperative day. The last follow-up after 30 months showed no recurrence of the IMT but clinical and radiological evidence of a persistent hepatic metastasis of the NETs. While plasma Chromogranin A remained suppressed by Sandostatin, the TGF β1 level was markedly elevated.DiscussionBased on the current literature and our previous experiences, we can state that IPT are an aberrant secondary immunological process possibly induced by excessive TGF β1 and not a neoplasia. Nevertheless, the tumorous behavior points to a continuity between inflammation and neoplasia. Differential diagnoses and the potential molecular pathogenesis are further discussed.