Intramuscular neurilemoma

Abstract

In this retrospective study, we analysed the clinical features of neurilemoma when it is located in muscle. Twelve patients had an intramuscular neurilemoma as shown on magnetic resonance (MR) scans and confirmed at operation. In six it was located in the upper limb, in five in the lower limb, and in one in the back. The mean age of the patients was 41 years (12 to 58). Nine complained only of a palpable mass and the other three of a mass with slight tenderness. None had neurological symptoms or signs, such as radicular pain, a positive Tinel sign, or motor weakness. There were no postoperative complications or recurrence of the tumour after a mean follow-up of two years (1 to 10).

Rare Form of Schwannoma as a Purely Hemorrhagic Cystic Tumor Located in an Intermuscular Plane

“…The following imaging characteristics describe the neurogenic origin of the tumors and are consistent with a diagnosis of schwannomas: 1) The "split-fat sign," ie, the lesion is surrounded by a rim of fat; this appearance is related to the displacement of the fat that normally surrounds the neurovascular bundle (7,8). 2) As a schwannoma is a neurogenic tumor, entering and exiting nerve roots are commonly visualized at both ends of a fusiform mass.…”

“…To the best of our knowledge, no previous reports have described a purely hemorrhagic cystic schwannoma (2,4,5,7). We present a case of a purely cystic schwannoma between the vastus lateralis, and the vastus intermedius muscles resembling a hemorrhagic ganglion cyst or a chronic hematoma.…”

“…2) As a schwannoma is a neurogenic tumor, entering and exiting nerve roots are commonly visualized at both ends of a fusiform mass. However, the entry and exit signs are not always seen when the affected nerve is a small muscular branch (7,8).…”

“…Magnetic resonance imaging (MRI) scans can be more useful in the preoperative diagnosis of the schwannoma than physical examinations (1,7,8).…”

“…These changes are usually partially visible in the tumors (1-6). Few reports have described a purely cystic schwannoma (2,4,5,7).…”