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Year : 2002  |  Volume : 50  |  Issue : 4  |  Page : 516--7

Diffuse neurofibroma of scalp.

AK Khan, S Deb, DK Ray, S Mandal, S Mukhopadhaya, S Mandal 
 Department of Neurosurgery, R.G. Kar Medical College and Hospital, Calcutta - 700 055, India., India

Correspondence Address:
A K Khan
Department of Neurosurgery, R.G. Kar Medical College and Hospital, Calcutta - 700 055, India.


Diffuse neurofibroma is an uncommon but distinct variety of neurofibroma, usually affecting trunk, head and neck regions of adolescents and young adults. The clinical features, gross macroscopic and histopathological findings are enunciated and the criteria for instituting the preferred modality of treatment for such lesions has been reviewed, stressing upon the need to exclude the neurofibromatoses preoperatively.

How to cite this article:
Khan A K, Deb S, Ray D K, Mandal S, Mukhopadhaya S, Mandal S. Diffuse neurofibroma of scalp. Neurol India 2002;50:516-7

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Khan A K, Deb S, Ray D K, Mandal S, Mukhopadhaya S, Mandal S. Diffuse neurofibroma of scalp. Neurol India [serial online] 2002 [cited 2020 Oct 21 ];50:516-7
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Full Text


Neurofibromas are benign tumors of peripheral nerves of neuroectodermal origin.[1],[2] The essential cells in neurofibromas, are of Schwann cell origin.[3]

Microscopically, neurofibromas are formed by a combined proliferation of all the elements of a peripheral nerve: axons, Schwann's cells, fibroblasts and perineural cells.[4] Schwann's cells usually represent the predominant cellular element.[4] The connective tissue stroma consists of a rich network of collagen fibers.[5]

Neurofibromas are usually solitary, but upto 10 per cent of patients have multiple lesions and a proportion of later have von Recrlinghausen neurofibmatosis.[2] Diffuse neurofibroma is an uncommon but distintive form of neurofibroma, which presents as a variably sized, often large area of marked dermal and subcutaneous thickening, most often in the trunk or head and neck region of adolescents or young adults.[1],[2] This lesion has also been termed 'paraneurofibroma' to indicate the extension of the tumor beyond the confines of the perineurium.[1],[6] Intracranial extension of extracranial variety of this tumor has also been reported.[7] Malignant transformation is rare,[1] and should be suspected in the presence of frequent mitosis, overtly expressed cell proliferation markers, and the presence of p53 in many tumor cells.[4],[8]

  ::   Case reportTop

A 28 year old female presented with a swelling of the scalp since childhood, which was gradually increasing in size. There was no family history or any cutaneous markers. There were no skin changes over the swelling. The swelling was overtly 12 cm x 12 cm in size, soft to firm, smooth, mobile, non-compressible, non-reducible, non-tender non-transilluminant with no impulse on coughing and ill-defined margins. There were no changes in the bone around the margins of the swelling nor any bruit over the swelling.

Plain skiagram of the skull showed no bony erosion and CT showed no intracranial extension. A provisional diagnosis of lipoma of scalp was made and operative excision was planned. The tumor was exposed with a lazy-S skin incision. The bulk of the grayish-white tumor was found to lie between the galea aponeurotica and the pericranium. The tumor was found to be highly vascular and blanket hemostatic sutures had to be applied in the peripheral scalp. Excision of the tumor bulk with meticulous hemostasis was achieved and the skin was closed primarily. Macroscopically the mass was unencapsulated, uniformly thick (thickness being about 1 cm), grayish-white in colour and soft to firm in consistency. The cut surface was homogeneous grayish white in colour.

Histopathological examination revealed spindle cells arranged in flowing streams interspersed with Wagner-Meissner corpuscles (distorted organoid structures resembling Pacini's corpuscles). Nuclei of the spindle cells were long, slender, with pointed ends and uniformly bland chromatin pattern. The stroma contained a rich network of collagen [Figure 1] and [Figure 2]. The patient had an uneventful post-operative period, save for a minor wound infection, which was treated successfully, and was discharged on the tenth postoperative day. There were no other complications during the one month follow up period.

  ::   DiscussionTop

Diffuse neurofibromas are uncommon soft tissue tumors, occuring in the head and neck region of adolescents and young adults.[2] Because of the lack of distinctive clinical characteristics, especially in

isolated lesions, it is difficult to diagnose the lesion preoperatively, and such lesions, remain largely, a histopathological diagnosis. Proper history-taking, physical examination, opthalmological and radiodiagnostic investigations are warranted in such cases, with special attention to detection of cafe-au-lait spots, Lisch nodules, bilateral acoustic tumors and family history of neurofibromas; to exclude neurofibromatoses.

The present case presented to us with a cosmetically unacceptable swelling, which was excised with a provisional diagnosis of lipoma. Apart from size and unsightlines[4] the possibility of life threatening hemmorhage calls for surgical removal of these usually benign tumors.[6] Though a small proportion of patients with neurofibromastosis type 1 may develop malignant peripheral nerve tumor (MPNST), for practical purposes, peripheral superficial neurofibromas never become malignant.[4] Enzinger and Weiss reported only one acceptable case of diffuse neurofibroma undergoing malignant change.[1] Once malignant change has supervened, therapy should consist of radical local excision or amputation.[1] In neurofibromatoses, the large number of lesions makes surgical excision impossible. In such cases, surgery has traditionally been reserved for lesions that are large, painfull or located in strategic areas where continued expansion would compromise organ function, and those in which malignant change is suspected.


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8Kindblom LG, Ahlde'n M, Meis-Kindblom JM et al : Immunohistochemical and molecular analysis of p53, MDM2, proliferating cell nuclear antigen and Ki 67 in benign and malignant peripheral nerve sheath tumors. Virchows Arch 1995; 427 : 19-26.