Non-functioning neuroendocrine tumor retrograde

Neuroendrocrine tumours are a type of epithelial neoplasm with a low incidence. They are clinically silent, subject to late diagnosis and are located primarily in the gastrointestinal tract. The only option for curing them is surgical treatment with R0 resection.^1,2 We report the case of an asymptomatic patient incidentally diagnosed with a neuroendocrine tumour located in the retrocaval region, which is rare for this type of tumour. An abdominal computed tomography (CT) scan showed a well-defined retroperitoneal mass measuring 59 mm × 48 mm, caudal to the left renal vein. In addition, a left infrarenal double inferior cava was observed as an anatomical variant, so this tumour was located posterior to the right primitive iliac vein (Fig. 1).

Figure 1.

(A) Abdominal CT scan showing a retrocaval tumour (arrow). (B) Macroscopic image of the tumour after surgical removal.

An octreoscan showed a retroperitoneal mass at L2-L3 with expression of somatostatin receptors, supporting the diagnosis of a neuroendocrine tumour.

The patient underwent surgery and complete surgical resection was achieved.

The definitive pathology results were a World Health Organization (WHO) grade II neuroendocrine tumour with a maximum diameter of 51 mm, disease-free resection margins with a Ki-67 of 10%, a mitotic index of 9 mitoses per 50 high-power fields and images of neoplastic infiltration of capillaries on the periphery of the lesion with involvement of 0/5 lymph nodes.