A retroperitoneal neuroendocrine tumour pre-diagnosed as an adrenal incidentaloma - a case report
Joanna Malicka1, Maria Kurowska1, Jerzy Tarach1 & Jolanta Kijek2
Introduction: Neoplastic lesions in the retroperitoneum may originate from kidneys, ureters, adrenal glands or peripheral nervous, connective, muscle and adipose tissues. Neuroendocrine tumours are exceptionally located in the retroperitoneum.
The case study: A woman aged 51, with a tumour of the left adrenal gland found incidentally during an ultrasound examination of the abdominal cavity, which was performed because of dysuria. A CT confirmed the presence of a 3.5-inch tumour with high initial density (22.6HU) in the retroperitoneum. It showed marked heterogeneous contrast enhancement (up to 98HU), which suggested foci of necrosis. A receptor scintigraphy (99Tc Hynic-TATE) did not show somatostatin analogue accumulation. The chromogranin A level was 3 U/l (n. 2.018.0). In a clinical evaluation hormonal activity of the tumour was excluded. Due to the anatomical features of the tumour and the nature of contrast enhancement in the CT, the patient with suspected adrenal cancer was qualified for urgent adrenalectomy. During surgery a 4-inch tumour was removed together with the left adrenal gland. Only in the postoperative evaluation it was established that the lesion had developed from an extra-adrenal tissue and had only adhered close to the adrenal gland and pressed it. The histopathological diagnosis was a neuroendocrine carcinoid. Immunohistochemistry was used to identify: cytokeratin MNF116 (−), synaptophysin (positive, but only in some cells), chromogranin (+/−), Grocott silver staining (+) and MIB1 1.7%. The patient has been monitored for 3 years and so far the disease has not progressed. The authors discuss a case study of a neuroendocrine tumour in a rare location. It imitated an adrenal cancer, however, postoperative histopathological examination showed that the carcinoid was not located inside the gland, but closely adhered to it.