Clinicopathological Study of Spectrum of Muscle Disorders in a Tertiary Care Hospital

Abstract

Introduction: The diagnostic approach to muscle disorders is often challenging due to paucity of literature, unavailability of ancillary facilities, affordability and improper sample collection. The role of pathologist in terms of categorising the muscle biopsy interpretation with limited resources plays an imminent role in guiding clinicians for further therapeutic approach. Aim: To analyse spectrum of various muscle disorders and to relate their clinical and histopathological findings. Materials and Methods: This was observational retrospective as well as prospective study of 63 muscle biopsies received during 10 years period from June 2009 to June 2019, at Department of Pathology in Grant Government Medical College, Mumbai, India. Slides of muscle biopsies received prior to June 2017 were restained and reviewed while muscle biopsies after this period were studied prospectively. Various histomorphological and histopathological (fascicular architecture, variation in size and shape of fibers, necrosis and degenerative/regenerative changes, nuclear characteristics, type and distribution of inflammatory cells along with interstitial changes) features were studied in detail and the findings were compared with similar previous studies. These findings when clubbed together with clinical, biochemical and Electromyography (EMG) findings, to guide the path towards appropriate diagnosis. Results: The present study evaluated and analysed 63 muscle biopsies, clinically, histopathologically and histomorphologically. Mean age was 30.6 years, 43 (68.25%) patients were males and 20 (31.75%) patients were females. A number of 12 (19.04%) patients were clinically diagnosed as having limbgirdle muscular dystrophy, followed by 9 (14.28%) patients as inflammatory myositis. Eight patients (12.69%) were diagnosed as Polymyositis (PM), five (7.93%) as Dermatomyositis (DM), one (1.58%) patient each of juvenile DM and inclusion body myositis. Histopathologically, the cases diagnosed were PM14 cases (22.22%) followed by muscular dystrophy (excluding limb-girdle muscular dystrophy)- 12 cases (19.04%) and limbgirdle muscular dystrophy- 9 cases (14.28%). Conclusion: Although molecular and genetic studies are need of hour, histomorphological features helps in proper categorisation of cases, however close liaison between pathologist and clinicians is essential and histopathological findings should only be interpreted in light of clinical manifestations and laboratory findings.

Keywords

• muscle biopsy
• muscle diseases
• muscle dystrophies
• polymyositis