Juvenile acid maltase deficiency presenting as paravertebral pseudotumour

European Journal of

Eur J Pediatr (1988) 147 : 372-376

Pediatrics

9 Springer-Verlag 1988

Juvenile acid maltase deficiency presenting as paravertebral pseudotumour T. C. lancu, A. Lerner, H. Shiloh, N. Bashan, and S. Moses Pediatric Research Unit, Carmel Hospital, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, and Pediatric Research Laboratory, Soroka Medical Center, Beer-Sheeva, Israel

Abstract. In addition to the infantile lethal form of glycogen storage disease with cardiomyopathy (GSD Type IIa, Pompe disease) 1,4 glucosidase or acid maltase deficiency has been reported in a few children and adults (GSD Type IIb or flc) erroneously thought to have muscular dystrophies. The clinical heterogeneity of the muscle involvement in these latter cases is illustrated in a 12-year-old boy presenting with a right lumbar mass, growth retardation, muscular weakness including difficulty in walking, and marked elevations of muscle and liver enzymes. Light- and electron-microscopic examination of specimens from the lumbar mass, apparently normal skeletal muscle and liver, showed typical changes consistent with the biochemical and enzymatic features of acid maltase deficiency. GSD Type IIb and IIc are more frequent than suspected, may present as local pseudohypertrophy and should be considered in patients with progressive muscle disease and abnormal serum enzymes. Key words: Glycogenosis - Lysosomal storage disease - Liver ultrastructure - Muscle ultrastructure - Acid maltase deficiency

Introduction The infantile form of acid maltase (alpha-l,4-glucosidase) deficiency is a lethal condition known as Pompe disease, GSD IIa or generalized glycogenosis [9, 15]. In recent years some cases have been reported in which acid maltase deficiency was recognized in children [6, 16, 20], adolescents [3, 20] and adults [4, 5]. The clinical presentations in these patients were variable, most cases initially being considered to be suffering from a 'muscular dystrophy' or 'myopathy'. In this report we describe unusual local manifestations, progressive muscle and liver involvement as well as relevant ultrastructural findings in this condition. Offprint requests to: T. C. Iancu, Department of Pediatrics, and Pediatric Research Unit, Carmel Hospital, 34362 Haifa, Israel Abbreviations: GSD = glycogen storage disease; SGOT = serum

glutamic oxaloacetic transaminase; SGPT = serum glutamic pyruvate transaminase; LDH = lactic dehydrogenase; CPK = creatinine phosphokinase; MUG = 4-methyl-umbelliferyl-alphat)glucoside

Case report and methods A 12-year-old Druze boy was 'referred for investigation of a right-sided paravertebral lumbar mass, after no diagnosis had been reached by previous surgical exploration. The fusiform, indolent swelling was apparently noted only a few weeks before, unaccompanied by fever or other complaints. A t surgery, the tissue appeared infiltrated by 'white-gray material'. Routine pathological examination showed the presence of severe changes within the muscle fibres, comprising either vacuoles, or accumulations of an unidentifiable PAS-positive material. Additional information became available after his admission to the Paediatric Department. He was born following a normal pregnancy and deIivery (birth weight 4100 g). His parents were first cousins and apparently healthy, as were another four siblings of both sexes. His growth rate was normal until the age of 4 years, after which it slowed down. He had difficulties in climbing stairs and walking, fell frequently and could not run. On clinical examination he was small and thin (height 128 cm, 1SD below 3rd percentile; weight 22 kg, 2 SD below 3rd percentile). The reduction in shoulder and hip muscle mass was conspicuous as was a lumbar lordosis (Fig. la, b). Despite surgery, the right lumbar mass was seen to arise directly from the paravertebral muscles, between the XIth thoracic and Vth lumbar vertebrae. The left-handed paravertebral muscles became prominent only when the patient was bending forward (Fig. lc). There was no pseudohypertrophy of the calf or other muscles. He had a waddling-type gait and wide based stance. Although muscle strength was markedly reduced, there was no tenderness or ataxia, and the Romberg test was negative. The neurological examination gave otherwise normal results. His intellectual and speech capacity were unaffected. The liver was hard and extended 4cm below the costal margin (span by Technetium-99 m sulphur colloid liver-spleen scan was 13.5cm; normal for the body size: 8-10cm). Although not palpable, the spleen was reported as increased in size by scintigraphy. Examination of the heart, including chest roentgenogram, electrocardiogram, and echocardiogram, gave normal results. Electromyography of the left deltoid and quadriceps muscles showed numerous motor unit potentials of decreased duration and amplitude, suggesting a myopathy. Areas of increased polyphasic potentials, alternating with areas of normal acitivity, were also observed. Numerous pseudomyotonic discharges were noted in the biceps.

373 dehydrogenase (LDH) 793-1130IU (normal,