|Year : 2014 | Volume
| Issue : 2 | Page : 55-56
Neurolipoma: A rare entity
Banyameen Iqbal1, Tushar Kambale1, Iqra Mushtaq2
1 Department of Pathology, Dr. D. Y. Patil Medical College and Research Center, Pune, Maharashtra, India
2 Department of Ophthalmology, Dr. D. Y. Patil Medical College and Research Center, Pune, Maharashtra, India
|Date of Web Publication||8-Dec-2014|
Department of Pathology, Dr. D. Y. Patil Medical College and Hospital, Pimpri, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
A lipoma is a common type of benign tumor and a neurolipoma is one of its variants. It is also referred to as neural fibrolipoma, fibrolipomatous hamartoma, intramural lipoma, and lipomatosis of nerve. The most common sites of presentation are the volar aspects of the hands, wrists, and forearms of young persons. The median nerve is most commonly involved. Lower-extremity cases are extremely rare. We report here a rare case involving the median nerve without any skeletal deformity occurring in a male patient. It usually presents with swelling associated with pain and tenderness.
Keywords: Benign neural tumours, lipoma, neurolipoma
|How to cite this article:|
Iqbal B, Kambale T, Mushtaq I. Neurolipoma: A rare entity. J Clin Sci 2014;11:55-6
| Introduction|| |
A lipoma is a common type of benign tumor and a neurolipoma is one of its variants. It is also referred to as neural fibrolipoma, fibrolipomatous hamartoma, intramural lipoma, and lipomatosis of nerve.  It usually manifests as a soft, slowly growing mass consisting of proliferating fibro-fatty tissue surrounding and infiltrating major.  nerves and their branches.  The most common sites of presentation are the volar aspects of the hands, wrists, and forearms of young persons.  The median nerve is most commonly involved. Lower-extremity cases are extremely rare.  Males are more affected than females. The lesions in about one-third of cases are associated with bone overgrowth and macrodactyly. We report here a rare case involving the median nerve without any skeletal deformity occurring in a middle-aged male patient.
| Case report|| |
We present a case of a 43-year-old male with swelling on the left forearm for the last 6 months. It is associated with pain and tenderness. The swelling was insidious on onset and is gradually increasing in size. There is no history of trauma or restricted mobility. The patient complained of cutaneous paresthesia and tingling sensation along the areas supplied by the median nerve. On examination the swelling is solitary, measuring 3 × 2 cm on the medial aspect of the left forearm, mobile; temperature is slightly raised and the overlying skin is normal. Past history, family history, or personal history revealed nothing significant. The general examination showed pallor and a temperature of 99°F. Lab investigations showed hemoglobin levels of 8.4 gm%, and the rest of the parameters were within normal limits. The systemic examination was unremarkable.
Fine-needle aspiration cytology (FNAC) was advised and the smears revealed only a few clusters of spindeloid cells with wavy nuclei as well as stellate cells in a hemorrhagic background [Figure 1]. The diagnosis of a benign spindle cell lesion was made and a biopsy was advised and performed.
|Figure 1: Cut section of the specimen showing firm yellowish area with a focus of hemorrhage|
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Grossly a single yellow white, fibro-fatty mass of 3 × 2 × 1 cm soft to firm in consistency was received. On cut section it was smooth and firm with a hemorrhagic area [Figure 2]. Microscopy showed mature adipose tissue admixed with fibrous tissue dissecting between and separating individual nerve bundles. Perineural fibrous tissue was seen arranged concentrically around the nerves. No evidence of lipoblastic activity or cellular pleomorphism was seen. The diagnosis was given as neurolipoma [Figure 3].
|Figure 2: FNAC micrograph showing a cluster of benign looking spindeloid cells in a hemorrhagic background, [Leishman ×20]|
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|Figure 3: Low-power view showing mature adipocytes, nerve bundles, and perineural fibrosis [H and E, ×20]|
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| Discussion|| |
Lipomas of peripheral nerves occur with sufficient frequency to pose problems in diagnosis.  In a lipoma of a nerve there is fat around nerve without infiltration within nerve bundles. A clear distinction from diffuse lipomatosis is not always possible histologically, but diffuse lipomatosis is a primary lesion of the subcutis and muscle and only secondarily affects nerves.  Neuroma and neurofibroma can be distinguished from neurolipoma by the nerve element. Neuroma and neurofibroma show a proliferation of neural elements, while neurolipoma shows atrophy of nerve bundles. The median nerve is affected in most cases.  Rarely are lesions found in other nerves such as ulnar and radial. Peroneal and cranial nerves are involved very rarely. , The diagnosis is usually made on the basis of microscopic findings. Immunohistochemistry is not essential for diagnosis, although the immunohistochemical profile of a neurofibrolipoma was first reported by Akisue et al. in his case report in 2002, showing CD34 antigen reactivity on fibrous spindle cells.  No ultrastructural finding is conclusive. It is usually seen in the age group of 11-39 years. Females predominate when lipofibroma is accompanied by macrodactyly, whereas males are more commonly affected by lipofibroma without macrodactyly. The present case is of a 43-year-old male. There is usually a slow-growing mass present. The patient may show increasing pain, tenderness, diminished sensation, or paraesthesia associated with the gradually increasing mass causing compression neuropathy. Carpal tunnel syndrome is a late complication of some lesions. There may be loss of muscle strength. Magnetic resonance imaging (MRI) scans are characteristic and pathognomonic and the diagnosis can be made preoperatively. 
| Conclusion|| |
Although lipomas are very common, however, a neurolipoma as one of the uncommon variants of lipoma, should always be kept in mind in the case of any lipoma presenting with pain and tenderness and especially with paresthesias or loss of function in the area of distribution of the affected nerve.
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[Figure 1], [Figure 2], [Figure 3]