Progressing nemaline myopathy in a patient repeatedly operated on the spine: clinical case and literature review

Abstract

Objective. To present a clinical case of a patient with spinal deformity associated with myopathy, which was initially undiagnosed and as- sessed as secondary myopathy after performed spinal surgeries. Material and Methods. Study design: clinical observation and review of the literature. A 51-year-old female patient has been repeated- ly operated on for scoliotic deformity of the spine with progressing neurological disorders. Clinical and complex radiological assessment (spinal telemetry in sitting position, CT, MRI) of the pathology was performed. In connection with the atypical course of the disease, a pathohistological study of muscle tissue fragments was performed with their fixation in a solution of 10 % neutral formalin. After histo- logical processing, the fragments were embedded in paraffin and stained with hematoxylin-eosin by the Masson trichromic method and by the PTAH method. The preparations were examined using the Pannoramic MIDI II BF hardware and software complex to obtain digital images using the Whole slide imaging technology in the Single layer and Extended focus modes and an AxioScope.A1 stereomicroscope with a digital camera. Results. Two patterns of distribution of nemaline rods of various density and configuration stained dark blue (by PTAH) were identified in sarcoplasm of parts of muscular tissues: diffusely throughout the myocyte and forming clusters of various sizes in transverse sections, and as filamentous structures – in longitudinal ones. Extensive fields of fatty degeneration, transformation of fibers into lipocytes, con- tracturely changed fibers, pictures of myophaga and areas of fibrosis of the interstitial space associated with residual myocytes were noted. Intramuscular nervous conductors were subjected to complete involution, singular nervous fibers were deformed, internal space was fibrotic. Neuromuscular spindles had unusually increased connective tissue capsule filled with lipocytes. Arterial vessels had fibrosis of t. adventicia and t. media, narrowed or obliterated lumen, and venous vessels were thin-walled and tortuous, which causes their permeability and can cause hemorrhage. The revealed changes in myocytes with the presence of nemaline rods are characteristic of primary nemaline myopathy. Conclusion. The atypicality of clinical manifestations, primarily of the neurological status in scoliosis, requires excluding neuromuscular disease by conducting a histopathological examination of the surgical material.

Keywords

• scoliosis
• neuromuscular scoliosis
• congenital myopathy
• nemaline rods
• fatty degeneration