Case 89: Neurofibroma

This English born 73 year old man had severe bronchitis, deafness and obvious neurofibromatosis. He was also extremely short. He had apparently been reasonably well until the night before his admission to hospital when he was found collapsed.
At autopsy he was a dwarfed elderly man, a mere 150 cm in length and most of his body was covered with skin lumps ranging in size from a few mm to large pedunculated lesions 5 cm in diameter. These neurofibromata were most numerous on the abdomen. He had chronic bronchitis and emphysema with cor pulmonale, ischaemic heart disease with a left ventricular scar and an old left cerebral infarct in the white matter lateral to the left caudate nucleus. In the stomach there were several leiomyomata. In addition to the cutaneous neurofibromata there were many neurofibromata affecting the cervical nerves, the sympathetic chain, the spinal ganglia and chorda equina.

Macroscopic pathology

Microscopic pathology

The slide is made from a neurofibroma of the dermis. Macroscopic examination shows an ovoid, eosinophilic mass lined by epidermis at the edges with ulceration of the tip.
Microscopic examination shows a diffuse proliferation of spindle cells with wavy nuclei (1) (2).
The intervening stroma has a fibrillary appearance. Numerous small blood vessels (1) (2) are seen. The lesion is non-encapsulated and there are no features of malignancy.

Normal central nervous system tissues

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Micro 1 of 2

Micro 2 of 2

Test yourself on the pictures of this case - Link to the central nervous system and muscle test pictures

Commentary

Neurofibromas are formed by the combined proliferation of all the elements of a peripheral nerve - axons, Schwann cells and fibroblasts. Grossly, they tend to be fusiform in shape, involving the whole nerve, or may result in diffuse tortuous enlargement of the nerve (plexiform neurofibroma). Superficial neurofibromas may present as small soft pedunculated skin lesions - as in this case. The presence of multiple neurofibromas suggests a diagnosis of von Recklinghausen’s disease, the most common autosomal dominant condition in humans.

Learning objectives

1. Recognise the features of a neurofibroma
2. Know the various types and clinical presentations of the condition