Teaching Case

A 15-year-old girl with epilepsy and learning difficulty was admitted with hypertension and abdominal pain. Physical examination revealed multiple dome shaped papules in the malar area and a right upper and lower quadrant palpable abdominal mass.

An initial abdominal ultrasonography revealed multiple hepatic (Fig. 1) and renal hyperechogenic lesions. The most prominent renal lesion was identified in the inferior pole of the right kidney, which appeared as a bulky solid and heterogeneous mass extending into the pelvis.
An abdominal MRI was performed showing multiple hyperintense T1 and T2 hepatic (Fig. 2) and renal (Fig.3) nodules with signal loss in fat-saturated images, consistent with macroscopic fat content. The kidneys were also enlarged, with coexisting cysts.
A brain MRI (Fig. 4) was obtained revealing cortical tubers and subependymal tubers lining the margins of both lateral ventricles. An enhancing nodule was observed in the region of right Monro’s foramen.
Finally, a high-resolution chest CT (Fig. 5) revealed some cysts surrounded by normal lung and scattered noncalcified lung nodules.

Tuberous Sclerosis (TS) is an autosomal dominant neurocutaneous syndrome characterized by the development of multiple hamartomas distributed throughout the body and has been considered to be caused by mutations of two tumour suppressor genes: TSC1 and TSC2 [1, 2, 3, 4].
Classically, TS demonstrates a triad of clinical features (Vogt Triad): mental retardation, seizures and facial angiofibromas; however, a full triad is only evident in 29% of cases [1].
The recently advocated criteria for diagnosis of TS consists of major [facial angiofibromas, hypomacules, cortical tubers, subependimal nodules, retinal hamartomas, lymphangioleiomyomatosis (LAM), renal angiomyolipomas (AML), cardiac rhabdomyomas, shagreen patches, ungual fibromas, subependymal giant cell tumors] and minor features (multiple pits in dental enamel, hamartomatous rectal polyps, bone cysts, cerebral white matter radial migration lines, multiple renal cysts, gingival fibromas, "confetti" skin lesions, retinal achromatic patches) [2].
 The diagnosis is considered definite in the presence of two major features or one major and two minor features [1, 2].
These criteria rely heavily upon imaging, which plays a crucial role in the diagnosis and management of TS. Infants and children who present with seizures and cutaneous manifestations of TS should promptly undergo brain imaging, usually with MRI. This examination alone can make a definite or probable diagnosis of TS [3]. The presence of a cardiac mass alerts to the possible diagnosis of TS and an echocardiography is also recommended in children with suspected TS [1, 3]. Renal imaging is helpful in confirming diagnosis in older children and adults by demonstrating renal cysts and AML [3]. Post-menarchal females with suspected TS can undergo a high-resolution chest CT scan to identify LAM [1, 3].
Therapeutics of TS are at present symptomatic [1, 2, 3]. Vigabatrin has been shown to treat infantile spasms in 80-100% of cases [1]. However, particularly epileptogenic focal tubers may need surgical resection [3]. Rapamycin can induce regression of brain astrocytomas associated with TS, and its effects in LAM and AML are promising [2, 3]. Benefits of anti-oestrogen therapy in LAM are unclear and lung transplantation is reserved for end-stage disease [1, 3]. Interventional radiology plays a more direct role in the treatment of AMLs by embolization [3]. Although recent advances in treatment have improved morbidity, the prognosis is still quite poor and 40% of patients die by the age of 35 years [2]. Radiologists should be familiar with syndrome features because early diagnosis can certainly influence individual outcome [3, 4].