Retroperitoneal schwannoma mimicking metastatic seminoma: case report and literature review

Abdominal Schwannoma Mimicking Lymph Node Metastasis in Rectal Cancer

Schwannomas are rare benign tumors that are often asymptomatic and identified incidentally on imaging studies undertaken for another purpose. Schwannomas arising from the vestibular nerve are the most common site of identification; however, schwannomas can arise extracranially in any peripheral nerve tissue. Here, we present a case study of a patient with a localized rectal adenocarcinoma who was found to have a retroperitoneal schwannoma initially felt to be a lymph node metastasis of his rectal cancer. The diagnosis of schwannoma was confirmed via biopsy, which resulted in changes to the patient's overall management including radiotherapy volumes and recommendation against neoadjuvant or adjuvant systemic therapy.

Robotic-assisted excision of a juxta renal retroperitoneal schwannoma

Retroperitoneal schwannoma is a rare benign tumor of the peripheral nerve Schwann sheath. We, herein, report the case of a 74-year-old woman who presented with vague abdominal pain. Computed tomography imaging revealed a retroperitoneal mass that is medial to the right kidney. The patient underwent robotic excision of the tumor with the pathology revealing schwannoma. We report this case due to the scarcity of this disease entity, especially at this location and to emphasize the indication and value of robotic technology in different pathological processes retroperitoneally.

Laparoscopically resected obturator nerve schwannoma: A case report

Obturator nerve schwannomas are very rare. To date, only nine cases have been reported in the English-language literature; none of these were diagnosed preoperatively. A 68-year-old woman was admitted with left lower abdominal pain. CT and MRI revealed a mass 30 mm in diameter in the left obturator fossa, suggesting a retroperitoneal tumor. Because CT and MRI revealed clear continuity with the left obturator nerve, this case was diagnosed as an obturator nerve schwannoma. Tumor enucleation was performed by laparoscopy. On histopathological examination, this case was diagnosed as a benign obturator nerve schwannoma. Postoperatively, the patient developed weakness of the adductor muscle but recovered within 6 months with rehabilitation therapy. Preoperative diagnosis of obturator nerve schwannomas is quite difficult, but careful inspection of CT and MRI is important to identify the original nerve of schwannoma preoperatively. Accordingly, laparoscopic resection is a good treatment option.

Hemorrhagic, calcified, and ossified benign retroperitoneal schwannoma: First case report

BACKGROUND

Schwannomas are mesenchymal tumors arising from the neural sheaths of peripheral nerves. They can almost develop in any part of the body, while head, neck and extremities are the most common sites. Occurrence in the retroperitoneum is rare. Schwannomas can show secondary degenerative changes including cyst formation, hyalinization, hemorrhage, and calcification, whereas the ossified retroperitoneal schwannoma was only reported in a malignant one.

CASE SUMMARY

We first present a benign ossified retroperitoneal schwannoma in a 61-year-old female. The mass was found by a routine health examination. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a well-defined mass in the area among duodenum, right liver, and kidney. Definitive preoperative diagnosis of the mass was difficult. By laparotomy, the mass was found in the retroperitoneum. We completely removed the tumor and gross specimen showed a mass with a capsule and 6 × 6 × 4.8 cm in size. Microscopic examination showed the tumor is composed of spindle-shaped cells with degenerative changes of hemorrhage, calcification, and ossification. Immunohistochemically, S-100 protein was strongly positive. Finally, the mass was diagnosed as a hemorrhagic, calcified, and ossified benign schwannoma in the retroperitoneum. The patient was followed up for a period of 21 months, during which she was well with no evidence of recurrence.

CONCLUSION

We report the first case of a benign retroperitoneal schwannoma with secondary degenerative changes including hemorrhage, calcification, and ossification. Precise preoperative diagnosis of the tumor is challenging even with multiple preoperative imaging modalities. After complete resection, patients with benign retroperitoneal schwanommas generally have good prognosis.