Retroperitoneal Malignant Peripheral Nerve Sheath Tumour: A Rare Case Report

Comprehensive neurosurgical and visceral surgical therapy of retroperitoneal nerve tumors: a descriptive and retrospective analysis

Nerve tumors in the retroperitoneal space are a rarity. Radical surgery according to soft tissue tumors can lead to persistent pain and neurological deficits. This study aims to evaluate clinical outcomes of patients treated by a visceral- / neurosurgical approach. 33 patients with a retroperitoneal nerve tumor underwent surgery between 01/2002 and 12/2022 at our department. A visceral surgeon provided access to the retroperitoneal space, followed by micro-neurosurgical tumor preparation under neuromonitoring. Clinical examination and MRI were performed 12 weeks after surgery and further 3 months (WHO grade > 1) or 12 months (WHO grade 1). Further examinations were based on MRI findings and residual symptoms with median follow-up time of 24 months. One patient was treated for two distinct masses resulting in a total of 34 histological findings. Schwannomas (n = 15; 44.1%) and neurofibromas (n = 10; 29.4%) were the most common tumors. Long-term improvements were noted in radicular pain (15/18 patients; 83.3%), motor deficits (7/16 patients; 43.8%), abdominal discomfort and pain (5/7 patients; 71.4%). Recurrences were observed in 3/33 (9,1%) patients. This study represents the largest series of retroperitoneal BPNSTs treated with microsurgical techniques. Prospective multicenter studies are warranted to establish standardized treatment guidelines.

Retroperitoneal solitary neurofibroma mimicking lymph node metastasis of colon cancer: a case report

BACKGROUND

A neurofibroma is a benign tumor that arises from Schwann cells and neurofibromas occur throughout the skin of neurofibromatosis type 1 (NF-1: Von Recklinghausen's disease) patients. A retroperitoneal solitary neurofibroma without any clinical signs of NF1 has been rarely reported. Herein, we present a case of a retroperitoneal solitary neurofibroma mimicking lymph node metastasis of colon cancer as well as a literature review.

CASE PRESENTATION

An 80-year-old woman with abdominal pain and nausea was transported and diagnosed with bowel obstruction arising from sigmoid colon cancer A colonic stent was inserted to alleviate the bowel obstruction. A computed tomography scan with contrast revealed a liver tumor in segment 3, and an enlarged lymph node around the abdominal aorta. Whole-body 18F-fluorodeoxyglucose-positron emission tomography-CT (FDG-PET-CT) examine revealed increased FDG uptake in the liver tumor and enlarged lymph node. Liver and distant lymph node metastasis were diagnosed and we made a plan for a two-stage operation of the colon cancer and the metastatic lesions because laparotomy resection was needed for the retroperitoneal lymph node. Laparoscopic sigmoid colectomy was performed first. Pathological examination showed a tubular adenocarcinoma. A laparotomy for the metastatic lesions was performed to ensure complete lymph node dissection secondly. Histopathological findings of the liver tumor showed metastasis of sigmoid colon cancer. However, the tissue regarded as the enlarged lymph node was diagnosed as a neurofibroma. No metastasis and recurrence were observed.

CONCLUSION

Although most neurofibromas are benign, malignant transformation of a neurofibroma is possible. PET-CT showed our patient had a high accumulated retroperitoneal tumor co-existing with colon cancer and liver metastasis. The treatment strategy of a solitary neurofibroma must be selected carefully considering the site of occurrence and the patient's background and aggressive resection of a tumor co-existing with another malignant tumor is needed.

Solitary Retroperitoneal Neurofibroma Associated With Deep Vein Thrombosis in a 40-Year-Old Male

A neurofibroma is a benign, non-encapsulated neoplasm of the peripheral nerve sheath. These tumors are a notorious manifestation of the autosomal dominant condition known as neurofibromatosis type 1, where they present as multiple, cutaneous masses with high malignant potential. On the contrary, benign solitary retroperitoneal neurofibromas (SRN) occur without any associated conditions and have rarely been documented. Our case is of a 40-year-old male who presented with a three-month history of painful calf swelling, refractory to over-the-counter painkillers which was later diagnosed as deep vein thrombosis (DVT). A computed tomography (CT) angiogram was done which revealed a mass in the retroperitoneum impinging on the inferior vena cava (IVC). Approximately one month later, the whole mass was surgically excised and histopathology confirmed the diagnosis of a neurofibroma. This case presentation proved to be novel as it highlights the evaluation and management of a rare SRN which resulted in extensive DVT.