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Q1: What is the diagnosis and what are the clinical features of this condition?
The underlying diagnosis is tuberous sclerosis. Tuberous sclerosis complex (TSC), described by Bourneville in 1880,1 is one of the neurocutanous syndromes. Inheritance is autosomal dominant with spontaneous mutation in 60%.12 Two loci on chromosomes 9 and 16 produce the phenotype, both encoding proteins with tumour suppresser function.3 Incidence is estimated as one per 6000 live births and a prevalence of one in 10 000.1 Diagnostic criteria were reviewed in 1998.4 Clinical features result from hamartomas affecting various organ systems. Cerebral manifestations occur in up to 95% of patients,1 which include cortical tubers, subependymal nodules, giant cell astrocytomas, epilepsy (60%), learning difficulties (40%),5 and autism (40%–45%).6 Skin involvement (90%–95%)1 includes facial angiofibroma, hypomelanotic macules, forehead fibrous plaques, Shagreen’s patches, ash leaf spots, and periungual fibromas (fig 1; page 661).2 Renal involvement includes cysts and angiomyolipomata (45%–66%),12 composed of blood vessels, smooth muscle, adipose and connective tissue. Typically they are benign and may be symptomless,7 though may differentiate to renal cell carcinoma in well under 5%8 and may occur bilaterally.9 Renal disease is a leading cause of death in patients with TSC.10 Pulmonary cysts and lymphangioleiomyomatosis occur exclusively in women.11 Retinal phakomas, dental pitting, cardiac rhabdomyomas, gingival fibromas, and rectal polyps are recognised features.1
Q2: What does the computed tomogram of the abdomen (fig 2; p 661) show?
The non-contrast computed tomogram shows grossly abnormal kidneys with enlarged focal areas of fatty change surrounded by streaky material largely replacing the renal tissue. A large uniform soft tissue mass is seen to arise from the anteromedial aspect of the right kidney.
Q3: What do the renal ultrasound scans (figs 3, 4, 5; p 661) show and what is the likely diagnosis?
The initial ultrasound (fig 3; page 661) shows a homogenous 10 cm mass in the mid-lower abdomen. Subsequent scans (fig 4 and 5; page 661) over a six week period show the mass to be reduced in size, with a more loculated irregular echo pattern consistent with resolving haematoma within a large section of angiomyolipoma.
The diagnosis is spontaneous haemorrhage into a renal angiomyolipoma in a patient with tuberous sclerosis. Intrarenal, perirenal, retroperitoneal, and intraperitoneal haemorrhage are well recognised complications of angiomyolipomata.1 Bleeding risk increases when they exceed 4 cm in size, and if symptomatic may require intervention with embolisation or nephric sparing surgery.12
Q4: What is the cause of the clotting abnormality?
A normal prothrombin time and prolonged activated partial thromboplastin time which is not reversed when the patients plasma is diluted 1:1 with normal platelet free plasma suggests lupus anticoagulant activity. Anticardiolipin antibodies were subsequently negative in this case, and clotting studies require follow up.
Spontaneous haemorrhage into a renal angiomyolipoma in a patient with tuberous sclerosis.