ULTRASTRUOTURAL STUDY OF SKELETAL MUSCLE IN MORPHOEA

SUMMARY.— Electron microscopic studies have been carried out in 2 cases of localized and one of generalized morphoea. Specimens were taken from pectoralis major, trapezius, quadriceps femoris and biceps brachii in areas of affected skin. The muscle fibre and its components showed various degrees of damage—vacuolization, absence of some bands and focal or marginal atrophy of some myofibrils. Band Z was the most resistant. No changes were seen in muscle capillaries. In both forms of morphoea the sarcoplasmic reticulum in some muscle fibres was widened at the expense of myofibrils. In both conditions some muscle fibres and their components were unaffected.