Clinical and radiological repercussions of plexiform neurofibroma in the pelvic region

Abstract

The authors report the case of a plexiform neurofibroma located in the pelvis, affecting the bladder, prostate and spine (lumbar/sacral), followed-up for three years and six months. Surgical removal was contraindicated and the patient underwent biannual clinical and radiological follow-up that did not demonstrate any tumor increase. The clinical manifestations of neurofibromatosis type 1 are variable, and the medical team should be attentive to further investigations, considering possible unexpected rare findings. Large pelvic masses may correspond to plexiform neurofibromas, so the diagnostic hypothesis of neurofibromatosis should be taken into consideration.

Keywords: Neurofibromatosis type 1; Pelvis; Plexiform neurofibroma.

Figure 1

Lumbosacral column MRI showing isointense ovoid and elongated images on T1-weighted, and hyperintense images on T2-weighted and STIR sequences. The lesions vary in size and are located at the level of the neural foramens, with extraforaminal extension.

Figure 2

Pelvic magnetic resonance imaging identifying a large expansile mass, with isointense signal on T1-weighted sequence and hypointense signal on T2-weighted sequence. Poor contrast uptake is observed in the prostate region and on the posterior bladder wall. The bladder is elongated, distended and anterosuperiorly displaced.

Figure 3

Magnetic resonance imaging demonstrating multiple nodular, stringshaped lesions distributed along the nerve roots of the sacral plexus, in the perivascular retroperitoneum, adjacent to the obturator muscles and in the periprostatic neurovascular bundle.