Primitive neuroectodermal tumours (PNETs) arise from pluripotent neural crest cells and are classified as either central or peripheral. Peripheral PNETs (pPNETs) arise outside the central nervous system and sympathetic chain. These rare neoplasms comprise only 1% of all sarcomas and have highly aggressive biological behaviour and dismal prognosis. Adolescents and young adults are typically affected. Only isolated case reports on pPNETs appearing in both typical and atypical sites can be found in the literature. Timely diagnosis of pPNETs is a challenge to clinicians and radiologists due to the disease's insidious onset and variable locations, coupled with the limited studies that focus on the imaging features of pPNETs. Hence, this article serves to review the imaging features of this rare tumour.
Contrast Media ; Diagnosis, Differential ; Diagnostic Imaging ; Humans ; Neuroectodermal Tumors, Primitive, Peripheral ; diagnosis

OBJECTIVE: Transrectal ultrasound (TRUS) has been widely used for guiding prostate implants, but not much for interstitial brachytherapy (IBT) of cervix cancer. The aim of our study is to report our experience with TRUS guided high dose rate (HDR) IBT in patients with carcinoma of uterine cervix. METHODS: During the year 2005-2006, 25 patients of cervical cancer not suitable for intracavitary radiotherapy (ICRT), were enrolled in this prospective study. We used B-K Medical USG machine (Falcon 2101) equipped with a TRUS probe (8658) having a transducer of 7.5 MHz for IBT. Post procedure, a CT scan was done for verification of needle position and treatment planning. Two weekly sessions of HDR IBT of 8-10 Gy each were given after pelvic external beam radiation therapy. RESULTS: A total of 40 IBT procedures were performed in 25 patients. Average duration of implant procedure was 50 minutes. There was no uterine perforation in any of 11 patients in whom central tandem was used. CT scan did not show needle perforation of bladder/rectum in any of the patients. During perioperative period, only 1 procedure (2.5%) was associated with hematuria which stopped within 6 hours. Severe late toxicity was observed in 3 (12%) patients. Overall pelvic control rate was 64%. CONCLUSION: Our experience suggests that TRUS is a practical and effective imaging device for guiding the IBT procedure of cervical cancer patients. It helps in accurate placements of needles thus avoiding the injury to normal pelvic structures.
Brachytherapy ; Cervix Uteri ; Female ; Hematuria ; Humans ; Needles ; Perioperative Period ; Prospective Studies ; Prostate ; Transducers ; Uterine Cervical Neoplasms ; Uterine Perforation