BILATERAL APPEARANCE OF ADIPOSE MEDIAL GASTROCNEMIUS MUSCLE - A CASE REPORT

Purpose: The gastrocnemius is normally a strong muscle for ankle plantar flexion as part of the triceps surae of the calf. Its two heads originate from the medial and lateral femoral epicondyles, respectively and converge at the middle half of the posterior leg as contributions of the Achilles tendon inserting on the calcaneus. The purpose of this case report is to describe a rare bilateral appearance of adipose medial gastrocnemius. Methods: A routine dissection was conducted on an 82-year old Caucasian female cadaver whose cause of death was dementia. Results: Complete adipose replacement of the medial head of gastrocnemius muscle was identified on both left and right legs. The adipose tissue was observed through the entire course of the medial gastrocnemius muscle belly from its origin at the medial epicondyle of the femur to its point of convergence as the Achilles tendon at the middle of the posterior leg. A longitudinal incision along the medial head of the gastrocnemius revealed oblique directed adipose tissue arrangement in a superomedial to inferolateral direction. Furthermore, no muscular atrophy, abnormality, or variation was observed throughout the remaining cadaver. Conclusions: It is commonly accepted that aging, sedentary life style, neurodegenerative muscle disorders, and metabolic disorders contribute to the replacement of skeletal muscle by adipose tissue. Frequently these mechanisms involve white-adipose infiltration of the sarcolemma resulting in a decreased percentage of muscle tissue comparatively. According to previous studies, long chain fatty acid uptake into skeletal muscle has been observed in partial sections of muscle and is linked with the muscle-specific protein marker caveolin-3 (Vistisen et al., 2004, p.603). This case involves complete transformation of skeletal muscle into adipose of the medial head of the gastrocnemius bilaterally, as opposed to partial, unilateral, or total gastrocnemius muscle transformation. No additional abnormality or pathological muscular changes were noted from the cadaver. This conversion of skeletal muscle to adipose involving half of the gastrocnemius bilaterally has never been reported before. With a most updated, thorough literature review, more in-depth research is warranted for this phenomenon.