Neuroendocrine tumor
see Pituitary neuroendocrine tumor.
Small-cell lung cancer AKA Oat cell carcinoma is a neuroendocrine tumor.
There have been significant developments in diagnostic and therapeutic options for patients with neuroendocrine tumors (NETs). Key phase 3 studies include the CLARINET trial, which evaluated lanreotide in patients with nonfunctioning enteropancreatic NETs; the RADIANT-2 and RADIANT-4 studies, which evaluated everolimus in functioning and nonfunctioning NETs of the gastrointestinal tract and lungs; the TELESTAR study, which evaluated telotristat ethyl in patients with refractory carcinoid syndrome; and the NETTER-1 trial, which evaluated Lu-DOTATATE in NETs of the small intestine and proximal colon (midgut). Based on these and other advances, the North American Neuroendocrine Tumor Society convened a multidisciplinary panel of experts with the goal of updating consensus-based guidelines for evaluation and treatment of midgut NETs. The medical aspects of these guidelines (focusing on systemic treatment, nonsurgical liver-directed therapy, and postoperative surveillance) are summarized in this article. Surgical guidelines are described in a companion article 1).
From tailgut cysts are rare; only 15 cases have been reported until now. A tailgut cyst with tethered spinal cord has not been previously reported, although both diseases are congenital anomalies in the early stage of gestation.
A 53-year-old man, who presented with gluteal pain and bladder dysfunction. MR images showed that a tumor of the sacral spinal canal extended into the retrorectal space and connected to a thickened fatty filum terminale, which was tethering the spinal cord.
Because of tumor malignancy on a CT-guided biopsy and the imaging data for involvement of presacral lymph nodes on imagings, Mitsuyama et al. performed total removal of the tumor. Pathological examination revealed neuroendocrine tumor (Grade 2) arising from a tailgut cyst. The patient received somatostatin analogue therapy after surgery, followed by local radiation because of the further enlargement of the lymph nodes. Later, the authors started everolimus therapy for the metastases to the retroperitoneal lymph nodes. He presented with no local recurrence or further disease progression at 28 months after surgery. The review indicated that tumors in grade 2 or 3 showed progressive clinical course after surgery and three of seven patients with biopsy were misdiagnosed.
The correct preoperative diagnosis of neuroendocrine tumors from tailgut cysts is difficult, but extremely important because grade 2 or 3 tumors show disease progression even after surgery. Presacral congenital tumors, such as tailgut cysts, have the potential of malignant transformation into neuroendcrine tumors or adenocarcinomas. Comorbidity of spinal cord tethering and tailgut cyst suggests some relationship to common developmental errors in embryogenesis 2).