Schwannoma pélvico retroperitoneal que simula un leiomioma: reporte de un caso y revisión bibliográfica / Pelvic retroperitoneal schwannoma presenting as a leiomyoma: Case report and review of literature

Resumen OBJETIVO Exponer el caso de una paciente con una masa pélvica que se reportó como mioma y resultó ser un schwannoma. CASO CLÍNICO Paciente de 53 años que consultó por dolor abdominal, lumbalgia, distensión, estreñimiento y dispareunia durante tres meses. La ecografía transvaginal sugirió un leiomioma. En la histerectomía laparoscópica se observó una masa retroperitoneal de 9 cm sobre el sacro. La resonancia magnética reportó un tumor sólido, presacro, de 8 cm. El diagnóstico histológico final fue: schwannoma celular S-100 positivo y actina de la musculatura lisa negativa. El seguimiento a los seis meses posteriores demostró disminución significativa del dolor abdominal inferior. CONCLUSIONES Los schwannomas se manifiestan, excepcionalmente, como masas pélvicas, como fue el caso aquí comunicado que se diagnosticó como fibroma uterino, pero que posteriormente se demostró era un schwannoma retroperitoneal. Este tumor pocas veces genera síntomas y cuando los hay suelen ser inespecíficos, por eso frecuentemente el diagnóstico es erróneo. Por la falta de características distintivas en los estudios de imagen el diagnóstico preoperatorio de un schwannoma no es fácil; su pronóstico es excelente y la escisión suele ser curativa.

Abstract OBJECTIVE Present the case of a patient with a pelvic mass which was reported as myoma and turned out to be a schwannoma. CLINICAL CASE We report a case of a 53 year old female that presented with abdominal and low back pain, also distention, constipation and dyspareunia for 3 months. Transvaginal ultrasound suggested leiomyoma. Laparoscopic hysterectomy was planned. On laparoscopy, a retroperitoneal 9 cm mass was seen over de sacrum. The procedure was stopped for further studies. Magnetic resonance images detected a large presacral solid, tumor of 8 cm. The patient was scheduled for laparoscopy with oncology group and the mass was resected. No complications were experienced intra or postoperatively. The final histological diagnosis was a cellular schwannoma, that was S-100- positive, and smooth muscle actin-negative. A follow up consultation 6 months later showed a significant improvement of the lower abdominal pain. CONCLUSIONS Schwannomas rarely present as pelvic masses. We report a woman with a pelvic mass initially diagnosed as a uterine fibroid but subsequently proven to be a retroperitoneal schwannoma. This rare entity is usually asymptomatic or has nonspecific symptoms leading to misdiagnosis. Preoperative diagnosis of a schwannoma is not easy for a lack of distinguishing features on imaging studies. The prognosis of schwannoma is excellent, and the excision is usually curative.

A Case of Cellular Schwannoma of the Lower Lip / 대한피부과학회지

Cellular schwannoma is a benign nerve sheath tumor which presents as a slowly growing tumor in the paravertebral region of the mediastinum and retroperitoneum in middle-aged adults. However it is extremely rare in the oral region. To our knowledge, this is the first report of oral cellular schwannoma in Korean dermatologic literature. Histopathologically, the tumor is characterized by the presence of compact spindle cells arranged into fascicles, variable nuclear hyperchromasia and pleomorphism, lack of Verocay bodies and typical predominance of Antoni A areas. We report a case of cellular schwannoma arising on the lip, which is a very rare location.

A Case of Cellular Schwannoma / 대한피부과학회지

Cellular schwannoma, a variant of schwannoma, is a rare, benign, nerve sheath tumor which presents as a slowly-growing tumor in the paravertebral region of the mediastinum and retroperitoneum in middle-aged adults. Cutaneous involvement is very rare. Histopathologically, the tumor is characterized by the presence of compact spindle cells arranged into fascicles, variable nuclear hyperchromasia and pleomorphism, lack of Verocay bodies and typical predominence of Antoni A areas. There may also be occasional increased mitoses and foci of necrosis. We report a case of cellular schwannoma involving subcutaneous tissue, which is a very rare location.

A Case of Cellular Schwannoma of the Retroperitoneum / 대한부인종양콜포스코피학회잡지

Cellular schwannoma is a variant of schwannoma, and is diagnosed as malignant tumor in over one fourth of cases because of its cellularity, mitotic activity and the occasional presence of bone destruction. This tumor is a tumor with low malignant potential and usually occurs in peripheral nervous system, mainly in the posterior mediastinum and retroperitoneal space. But pelvic retroperitoneal cellular schwannoma is very rare. Recently, we experienced a case of pelvic retroperitoneal cellular schwannoma in a 42-year-old woman; in reporting the case a brief review of the literature is included.

Cellular Schwannoma of the Cervical Spine in an Infant: A Case Report

Cellular schwannoma is a very rare benign tumor involving peripheral nerves, mimicking malignant nerve sheath tumor in histological appearance. It is a clinico-pathological variant of benign schwannoma characterized by a high cellularity, increased mitotic figures and occasional presence of bone destruction. A 6-month-old female patient was admitted with progressive quadriparesis. Magnetic resonance imaging of the cervical spine showed a well-enhancing extramedullary mass on the C4 to C6 area. Total laminectomy was performed on C4-7, and intradural extramedullary tumor was removed. Histologically, the tumor was composed of proliferated spindle cells. Most of the tumor was composed of Antoni A area with hypercellular spindle cells arranged in fascicular pattern. The tumor cells showed mild atypism with mitotic figure upto 4/10HPF and diffuse, strong S-100 protein immunostaining. The patient was improved postoperatively.

Cellular Schwannoma Arising in a Facial Nerve

Cellular schwaninoma is a variant of schwannoma, which is characterized by predominance of cellular Antoni A area, presence of mitotic activity, nuclear hyperchromasia, pleomorphism, and absence of Verocay body. These pathologic features often prompted a misdiagnosis of malignancy. However, the clinical outcome has indicated the benignity of the tumor. We have experienced a case of cellular schwannoma arising from right facial nerve with right hemifacial weakness and erosion of mastoid process. Grossly, it was a 3.5 x 3 cm sized and relatively well encapsulated mass with yellowish, friable cut surface. Microscopically, cellular growth with moderate cellular pleomorphism and some mitotic activity (5/40 HPFS, up to 2/HPF) were noted. Immunostaining for S-100 protein showed diffuse strong positive reaction.