The Osseous Lesions of Tuberous Sclerosis

Abstract

It is a generally accepted fact that there is a group of closely related congenital malformations which affect primarily ectodermal structures (skin, nervous system, etc.), but which may also present abnormalities in structures of mesodermal and, to a lesser degree, endodermal origin. Although not mutually exclusive in their manifestations, three syndromes in this group are particularly well defined and, as a result, have attracted most attention. They are (1) Recklinghausen's neurofibromatosis, (2) Bourneville's tuberous sclerosis, and (3) Sturge-Weber cephalotrigeminal angiomatosis. Each syndrome has fairly characteristic roentgenologic signs, which we have been trying to delineate more clearly by a systematic study of large series of patients with fairly typical clinical findings. By far the most fruitful site of roentgenologically demonstrable lesions to date has been the osseous system. In 1948 Holt and Wright (1) published an analysis of the skeletal x-ray findings of 127 unequivocal cases of generalized neurofibromatosis seen at the University of Michigan Hospital between 1935 and 1947. Since that time, an additional 52 patients with neurofibromatosis have been studied at the same source, and it appears that scoliosis, erosive defects: disorders of growth, bowing and pseudarthrosis of tubular bones, intra-osseous cystic lesions, or a variety of other bony defects occur in approximately 30 per cent of these patients. With a few exceptions, this analysis is not unusual from the standpoint of the types of lesions encountered, but the incidence of these skeletal abnormalities was found to be far greater than the figure of 7 per cent widely quoted in the medical literature. In the light of this apparent discrepancy, it seemed reasonable to assume that osseous lesions in the other hereditary congenital ectodermoses might be more common than we have previously been led to believe, and this study of tuberous sclerosis was undertaken. Although tuberous sclerosis was first recognized as a clinical syndrome by Bourneville (2), in 1880, it is of considerable interest that von Recklinghausen (3) reported a case in 1863, nineteen years before his classical description of the related syndrome of neurofibromatosis appeared. Tuberous sclerosis gets its name from the potato-like nodules occurring in the brain substance, which constitute the the nodules may calcify, particularly those in and about the basal ganglia. Clinically, patients with classical tuberous sclerosis present the triad of facial adenoma sebaceum, mental deficiency, and convulsions. Retinal tumors (phakomas) are just as common as they are in the other congenital ectodermoses, and renal tumors of the mixed embryonal type occur in a large percentage of cases. The occasional manifestations of defective development and tumor or cyst formation in the lungs; heart, liver, adrenals, and other structures, lead to a wide variety of additional clinical findings which will not be considered in this paper.