Schwannomas of the Spinal Nerve Roots

The tumors constitute about 15% to 30% of spinal tumors. They are more common on the sensory roots, preferentially occurring on the cauda equina.

Clinically, they present with pain and sensory and motor deficits in a radicular distribution. If they reach a large size, symptoms and signs of spinal cord compression develop. Hourglass or dumbbell schwannoma refers to extension of the tumor through the intervertebral foramen into the mediastinum or peritoneal cavity.

Intraparenchymal schwannomas are rare in the brain or spinal cord. They derive from Schwann cells of the nerves that supply small arteries or from ectopic Schwann cells.

Grossly, schwannomas are encapsulated, moderately firm, round or lobulated light tan tumors with the nerve stretching over the capsule. (Figs. 11.34 and 11.35) Cut surfaces contain small cysts and old and fresh hemorrhages.

Nerve Van Gieson

figure 1 1.35

A. Peripheral nerve neurinoma (myelin stain). B. Intradermal neurinomas (van Gieson stain).

figure 1 1.35

A. Peripheral nerve neurinoma (myelin stain). B. Intradermal neurinomas (van Gieson stain).

Histologically, two patterns are distinguished. The Antoni type A schwannoma consists of spindle-shaped cells with bipolar processes and small elongated nuclei arranged in interwoven fascicles. The cells immunoreact for S-100 protein. Mitosis is unusual. The nuclei tend to align in rows, giving the tumor a palisading pattern. Palisades around eosinophilic fibrillary areas form the characteristic verocoy bodies (Fig. 11.34). The Antoni type B schwannoma has a loose structure, with small stellate and fusiform cells situated in a mucoid matrix. Necrosis, cysts, hemorrhages, and hyalinized blood vessels are common (see Fig. 11.34).

Peripheral Neuropathy Natural Treatment Options

Peripheral Neuropathy Natural Treatment Options

This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.

Get My Free Ebook


Post a comment