Bilateral plexiform neurofibromas of the brachial and lumbosacral plexuses

Neurofibroma plexiforme bilateral dos plexos braquial e lombossacral

LETTERS

Bilateral plexiform neurofibromas of the brachial and lumbosacral plexuses

Neurofibroma plexiforme bilateral dos plexos braquial e lombossacral

Fernando H. Souza^I; Carlos B. Dabdoub^I; Silvya N. Bernardino^II; Elisabeth Nascimento Silveira^III; Silvio Litvin^IV; Hildo Azevedo-Filho^I

^IDepartment of Neurosurgery, Restauração Hospital, Recife PE, Brazil

^IIDepartment of Neurology, Hospital Getúlio Vargas, Recife PE, Brazil

^IIIDepartment of Nursing, Restauração Hospital, Recife PE, Brazil

^IVDepartment of Radiology, Restauração Hospital, Recife PE, Brazil

^{Correspondence}

Neurofibromatosis type 1 (NF-1) is one the most common autosomal dominant conditions affecting the nervous system¹. Plexiform neurofibroma (PN) is a benign tumor that basically defines the diagnosis of NF-1. These entities consist of multiple, twisted masses that grow along the axis of a large nerve, infiltrating and separating normal nerve fascicles. Malignant transformation is the main associated complication. Surgery is frequently reserved until PNs have progressed to the point of causing functional compromise, esthetic deformity or pain². This paper describes a case of plexiform neurofibromas of the brachial and lumbosacral plexuses, with presentation of the clinical and radiological findings.

CASE REPORT

An 18-year-old female patient was referred to a neurosurgery reference service with a history of mass lesion in the left cervical region, progressing to the right cervical region two months after the onset of symptoms. Physical examination revealed a nodule, painless upon palpation, in both cervical regions (Fig 1). "Café au lait" spots were seen on the patient's back and cutaneous and subcutaneous neurofibromas were seen over the extremities. The patient reported family history of NF-1, but she had not undergone any clinical follow-up. Neurological examination was normal.

Magnetic resonance imaging (MRI) of the brachial plexus was solicited and revealed the T2 weighted sequence, multiple, hyperintense, lobular, solid, expansive tumors in the distribution of the brachial plexus bilaterally extending to the anterior mediastinum and invading the spinal canal (Fig 2). Lumbosacral plexus MRI showed impairment of both plexuses and suggested the presence of a tumor toward the lumbosacral neural foramens (Fig 3) and its extension to the pelvic region (Fig 4).

An incisional biopsy was performed on the left cervical tumor and the histological findings were compatible with neurofibroma.

During the four-year follow-up involving imaging exams, the patient had been asymptomatic and free of neurological deficit. Thus, the decision was to maintain conservative management.

DISCUSSION

PN is a common manifestation of NF-1. This entity may be classified as a benign peripheral nerve sheath tumor that involves multiple nerve fascicles or branches of major nerves³.

MRI is the method of choice for the diagnosis and follow-up of neurofibromas. In T1 weighted image, a PN is isointense in relation to muscle tissue. In T2 weighted sequence, a PN is seen as a hyperintense, homogeneous image with "target sign", owing to the central fibrous tissue surrounded by myxoid tissue⁴.

Malignant transformation is the leading complication of PN. The lifetime risk of this transformation is estimated at 15 to 20% in patients with NF-1⁵. Clinical signs of malignant degeneration include the emergence of consistent pain, neurological deficit and an increase in the tumor mass. In the present case, the patient did not present clinical signs of malignant transformation throughout the entire follow-up.

The treatment of PNs in patients with NF-1 consists of regular follow-up examinations involving serial physical evaluations and neuroimaging studies². This was the conduct used in the present case.

Received 24 May 2012;

Received in final form 11 July 2012;

Accepted 18 July 2012

Conflict of interest: There is no conflict of interest to declare.

• 1. Williams VC, Lucas J, Babcock MA, et al. Neurofibromatosis Type I Revisited. Pediatrics 2009;133:123-124
• 2. Serletis D, Parkin P, Bouffet E, et al. Massive plexiform neurofibromas in childhood: natural history and management issues. J Neurosurg 2007;106:363-367
• 3. Al-Otibi M, Rutka JT. Neurosurgical implications of neurofibromatosis type I in children. Neurosurg Focus 2006;19:E2
• 4. Krandsdorf MJ, Murphey MD. Neurogenic tumors. In: Krandsdorf MJ (Ed). Imaging of soft tissue tumors. 2nd ed. Philadelphia, USA: Lippincott Williams & Wilkins, 2006:335-348.
• 5. Anghileri M, Miceli R, Fiore M, et al. Malignant peripheral nerve sheath tumors: Prognostic factors and survival in a series of patients treated at a single institution. Cancer 2006;107: 1065-1074.

Publication Dates

• Publication in this collection
  05 Feb 2013
• Date of issue
  Feb 2013