Nemaline bodies of skeletal muscle fibers of the neck in a case of pharyngeal cancer.

Nemaline bodies were found in the regenerating muscle fibers of the neck of a 74-year-old Japanese male with pharyngeal cancer. Histologically, the nemaline bodies were needle-shaped structures and hematoxophilic with phosphotungstic acid-hematoxylin stain. Electron microscopic examination suggested that they arise as extensions of the Z bands. Although nemaline bodies occur in a variety of pathological conditions other than nemaline myopathy, their occurrence in regenerating skeletal muscle fibers invaded by cancer has not been reported previously. The pathogenesis of the nemaline body formation in the present case is discussed.