|Year : 2023 | Volume
| Issue : 1 | Page : 68-70
A case of solitary neurofibroma involving the lower limb in a young tribal girl
Alisha Kalyanpur1, Royson Dsouza1, Binu Kurien2
1 Department of Surgery, ASHWINI, Gudalur Adivasi Hospital, Kothervayal, Nilgiris, Tamil Nadu, India
2 Department of Orthopedics, St. John's Medical College Hospital, Bengaluru, Karnataka, India
|Date of Submission||02-Aug-2022|
|Date of Decision||19-Oct-2022|
|Date of Acceptance||20-Oct-2022|
|Date of Web Publication||17-Jan-2023|
Dr. Royson Dsouza
Ashwini - Gudalur Adivasi Hospital, Kothervayal, Nilgiris - 643 212, Tamil Nadu
Source of Support: None, Conflict of Interest: None
We describe a 17-year-old girl who presented with a nontraumatic gradually progressive swelling in the right leg for 2 months. Clinically, there was a diffuse swelling involving the lower third of the lateral aspect of the right leg, which was firm and nontender. There were no similar swellings elsewhere. The radiological findings were inconclusive and she underwent an excision biopsy. Histopathology revealed features consistent with a neurofibroma. Solitary neurofibromas of the lower extremity are extremely rare benign lesions, having nonspecific clinical and radiological features. Histopathology is the mainstay of the diagnosis. Wide local resection is mandated as the treatment as these lesions have a propensity for recurrence.
Keywords: Management of solitary neurofibroma, neurofibroma of the fibula, solitary neurofibroma in an adolescent, solitary neurofibroma
|How to cite this article:|
Kalyanpur A, Dsouza R, Kurien B. A case of solitary neurofibroma involving the lower limb in a young tribal girl. Curr Med Issues 2023;21:68-70
| Introduction|| |
Neurofibroma is a benign soft-tissue tumor arising from the peripheral nerve sheaths. It is well described in the literature as part of the autosomal dominant systemic disease, Neurofibromatosis 1 (or von Recklinghausen disease), along with Lisch nodules, café-au-lait spots, axillary freckling, skeletal abnormalities, and significant family history. The genesis of neurofibroma is said to be homozygotic loss of the NF1 gene on chromosome 17. Isolated neurofibromas are less common and mostly found in the soft tissues of the head-and-neck regions. Malignant transformation of solitary neurofibroma is rare but 5% of neurofibromatosis-associated neurofibromas can develop into malignant sarcomas.
In the current report, we describe a case of a solitary neurofibroma of the distal third of the right leg in a 17-year-old girl. However, the biopsy was reported to be suggestive of neurofibroma. To the best of the authors' knowledge, there have been no prior reports of a solitary neurofibroma involving the lower extremity in young or old. The clinical features, differentials, and the management in a secondary tribal hospital are discussed, with a relevant review of the literature.
Consent was obtained from the patient's family for her case to be reported.
| Case Report|| |
A 17-year-old girl from the Paniya tribe of the Nilgiris, Tamil Nadu, presented with a swelling in the distal third of her right leg, which was noticed 2 months prior and gradually grew to the size of a lemon over 2 months. She reported occasional nonradiating pain over the swelling, aggravated with pressure. She did not give any history of trauma, fever, or skin changes. Her appetite was normal and she did not complain of loss of weight. She had no contact history with tuberculosis or symptoms suggestive of tuberculosis. No family members had similar complaints.
Her general physical and systemic examinations were unremarkable. On local examination, there was a swelling in the lateral aspect of the distal one-third of the right leg, measuring 6 cm × 3 cm. It was firm in consistency, noncompressible, with a smooth surface with restricted mobility. There was no local rise in the temperature or tenderness, and the overlying skin was stretched but normal. Skin was pinchable over the swelling, but mobility was restricted. Her distal neurovascular examination was normal. There were no other similar swellings in the body.
Relevant blood tests including inflammatory markers (erythrocyte sedimentation rate and C-reactive protein) were within the normal limits. X-ray of the right leg showed a soft-tissue shadow overlying the distal fibula with cortical hyperostosis in the underlying bone and no periosteal reaction [Figure 1]. Ultrasonography of the soft tissue did not show any collection. For further characterization of the lesion, magnetic resonance imaging was done. This showed a soft-tissue mass in the anterior compartment of the leg which closely approximated the fibula and extended into the subcutaneous fat plane. The mass was relatively homogeneous in signal intensity and was hyperintense on T2-weighted images as well as inversion recovery sequence [Figure 2]. Fibula also showed reactive cortical thickening. Possibilities suggested by the radiologist included soft-tissue tumor or vascular malformation.
|Figure 1: X-ray of the right leg showing soft-tissue swelling with cortical hyperostosis of the underlying bone.|
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|Figure 2: Magnetic resonance imaging of the right lower leg showing homogeneous mass, hyperintense on T2-weighted images, closely approximating the fibula and extending into the subcutaneous fat plane.|
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The swelling showed no resolution with IV antibiotics, and hence, she was planned for a biopsy. Intraoperatively, there was a soft-tissue swelling, adherent to the fibula, with pressure atrophy of the surrounding muscles. The swelling was excised with an adjacent fibula with a margin of 1 cm. Her postoperative period was uneventful. On a 3-month follow-up, she was doing well with no evidence of recurrence.
On gross histopathology, there was an ill-defined soft-tissue lesion attached to the bone and the adjacent muscle was unhealthy. Microscopically, there were large bundles of fibro-collagenous stroma, closely interlinked with neural bundles, many of which were much thickened. Closely admixed were small and medium-sized vessels and mature adipose tissue. The lesion entrapped the adjacent bone as well. The pathological features were consistent with neurofibroma [Figure 3].
|Figure 3: Histopathological examination of the swelling showing neural bundles, fibro collagenous stroma, blood vessels, and adipose tissue.|
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| Discussion|| |
Solitary neurofibromas, although not uncommon, are rarely found in the lower extremities. One case has been reported of the fibula being involved in the systemic disease Neurofibromatosis-1. However, to the best of the authors' knowledge, no cases in the literature have been reported of a solitary neurofibroma involving the fibula [Table 1]. There is a possibility that this could be the part of a generalized neurofibromatosis. However, on a thorough clinical examination, no other lesions were found elsewhere in the body.
Neurofibromas are generally slow-growing painless tumors. However, pain and neurological deficits are common due to their infiltrative nature. Itching and discomfort also occur in growing neurofibromas. In our case, the patient presented with pain, probably due to the infiltration of the neurofibroma into the periosteum of the fibula.
Evaluation of a neurofibroma includes radiological imaging and histopathological examination. Radiologically, MRI usually shows an isointense or hypointense lesion on T1-weighted images and hyperintense on T2-weighted images. Grossly, neurofibroma appears as a well-circumscribed tumor which is glistening tan-white with no degenerative changes. Microscopically, there are 10 variants, including classic, cellular, myxoid, hyalinized, epitheloid, plexiform, diffuse, pigmented, granular cell, and Pacinian. The diagnosis of a soft-tissue tumor can be ambiguous. Hence, histopathological confirmation with biopsy proved essential in the diagnosis.
Most authors believe that complete surgical excision is the mainstay of treatment for soft-tissue tumors such as neurofibroma, keeping in mind the following surgical principles: A lengthy incision for maximum proximal and distal exposure, extension of the incision to include the tumor capsule, removal of the tumor as a single mass if possible, and excision of the capsule at the end of the procedure. In our case, the excision of bone en masse with the swelling confirmed the diagnosis, ruled out alternative diagnoses as well as served as definitive management.
| Conclusion|| |
Solitary neurofibroma is uncommon but should be considered as a differential diagnosis of swellings in the lower extremities. Radiological features of neurofibroma are nonspecific and can mimic an infective or malignant process, if adjacent to bone. Excision biopsy serves as a diagnostic as well as a treatment tool for benign soft-tissue swellings. Complete excision is the mainstay of treatment of neurofibroma. Benign bone tumors can be diagnosed and satisfactorily managed in a secondary care hospital.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
The authors would like to thank Staff of Ashwini Gudalur Adivasi Hospital and Adivasi Munnetra Sangam.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]