Unilateral calf hypertrophy and radiculopathy: an unusual association.

To cite: Daniel A, Eugénio G, Silva J, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2016-217744 DESCRIPTION A 46-year-old man presented with a 3-year history of progressive enlargement of the right calf. The patient denied local pain, weakness or paraesthesia of lower limbs. Physical examination confirmed calf enlargement with no neurological deficits (figure 1). Laboratory tests revealed mild elevation of creatine kinase (554 U/L). MRI showed an increased volume of the muscles of the posterior compartment, with signs consistent with local myositis (figure 2). Electromyogram revealed findings of S1 radiculopathy. A muscle biopsy was performed which confirmed a denervation process and revealed a discreet focal myositis process (figure 3). Imaging study of the lumbar–sacral spine, conducted by CT, confirmed a disc herniation, leading to compression of the right L5 and S1 roots (figure 4). Neurogenic muscle hypertrophy secondary to S1 radiculopathy is a rare but well-documented phenomenon. The pathophysiology is unclear, but it may be secondary to an abnormal electrical activity or occur as a result of increased workload imposed on the non-denervated fibres.