How Common Are Benign Retroperitoneal Tumors? A Case Series with Review of Literature.
YaminiChitra V, Paramesh K N and Rithin Punjala Sai
World Journal of Surgical Medical and Radiation Oncology 2015, 4:1
Benign retroperitoneal tumors are usually rare and form 4%-25% of all retroperitoneal tumors in the past. Due to advanced imaging modalities the number of incidental tumors has increased and now forms up to 60% of all retroperitoneal tumors. Based on imaging techniques, various diagnostic criteria have been developed to ascertain origin and to determine the benign or malignant nature of these tumors. Large sizes, symptoms, heterogenous lesions on imaging, are considered as signs of malignancy. But surprises do occur.
We present two cases of benign retroperitoneal tumors, first a case of massive retroperitoneal tumor in a 30 year old male with vague abdominal pain. Preoperative computed tomography revealed heterogeneously enhancing mass 20×15×12 cm with cystic areas and calcifications, suspected to be malignant and of pancreatic origin. Peroperatively it was of retroperitoneal origin and pancreas was compressed &pushed superiorly. Patient underwent total excision of tumor. Second case, a 24 year male with incidentally diagnosed presacral lesion, 7×7cm size, with extension into S1 sacral foramina. Heterointensity on T2 W magnetic resonance imaging gave a suspicion of malignant nerve sheath tumor and the tumor was excised in toto. Both the patients postoperative histopathology showed a benign schwannoma and immunohistochemistry was positive for S 100. Both patients are tumor free 12 months and 7 months respectively after surgery.
Benign retroperitoneal tumors can grow to a large size before they become symptomatic. Massive size is often misleading regarding both site of origin of tumor and the benign or malignant nature of it. Preoperative imaging will not always give a clue to the nature of it making preoperative diagnosis of benign tumors very difficult. But complete excision of tumor gives excellent results.
Schwannoma, Retroperitoneum, Computed tomography, Magnetic resonance imaging, Immunohistochemistry