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.

Final diagnosis

Spontaneous haemorrhage into a renal angiomyolipoma in a patient with tuberous sclerosis.