[A 54-year-old man with progressive proximal muscle atrophy and gynecomastia]

We report a 54-year-old man with progressive proximal muscle atrophy and gynecomastia. The patient had an insidious onset of weakness in his lower extremities at age 14, in that he noted a difficulty in standing up from a chair. Soon after he noted some difficulty in climbing up stairs. At age 35, he noted weakness in his arms; his weakness slowly progressed in that he became unable to walk or stand alone before 40 years of age. He also noted gynecomastia at that age. He was admitted to our hospital for the work up on September 16, 1993, when he was 54-year-old. On admission, he was alert and oriented; his BP was 150/70 mmHg; he had bilateral gynecomastia, however, no other skeletal deformities were found. On neurologic examination, he was mentally sound without dementia, and his higher cerebral functions were normal. Cranial nerves also appeared intact without facial atrophy, dysarthria, or dysphagia; no atrophy was noted in the tongue. He had marked muscle atrophy in both upper and lower extremities more marked in the proximal portions; muscle strength was approximately in the range of 2/5 to 3/5 in the proximal parts, and 4/5 in the distal parts in both upper and lower extremities. No fasciculation was noted; muscle tone was flaccid; no ataxia was present. Deep reflexes were either lost or markedly diminished. No Babinski sign was noted. Sensation was intact. Laboratory examination revealed normal blood counts; serum CK was slightly increased to 131 IU/l; ECG showed complete right bundle branch block; EMG revealed no active units in the right biceps brachii, deltoid, quadriceps femoris, and triceps surae muscles; in other muscles tested, motor unit potentials of low amplitude and short duration were seen; in the right tibialis anterior muscle, however, motor unit potentials with an amplitude up to 6 m V were also seen. Nerve conduction velocities were normal. A diagnostic procedure was performed. He was discussed in the neurological CPC, and the chief discussant arrived at the conclusion that this patient had Becker type of progressive muscular dystrophy. In her differential diagnosis, the possibility of Kennedy-Alter-Sung syndrome was discussed because this patient had gynecomastia. However, the discussant excluded that possibility because of absence of both bulbar symptoms and typical neurogenic changes in his EMG. The diagnostic procedure was a muscle biopsy on the left tibialis anterior muscle. Histologic observation on HE stained specimens revealed marked inequality in the muscle fiber diameters, increase in endomysial nuclei, proliferation of connective tissue, and fiber splitting.(ABSTRACT TRUNCATED AT 400 WORDS)