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Quiz page answers November 2004
AJKD
QUIZ PAGE ANSWERS NOVEMBER 2004
A 57-year-old woman presented with renal failure (serum creatinine, 4.8 mg/dL [424 mol/L]), anemia (hematocrit, 25%), microhematuria, and severe hypertension. She had no history of seizures or mental retardation. She had no skin lesions on examination.
Figure 33C.
What do you observe on MRI of the patient’s abdomen?
Axial, contrast-enhanced, T1-weighted MRI of the abdomen showed increased kidney volume with multiple angiomyolipomas. There also was edema in the superior pole of the right kidney (arrow). Contrast-enhanced MRI of the brain was done.
Figure 33D.
What do you observe on MRI of the patient’s brain?
MRI of the brain revealed ill-defined areas of increased signal intensity on T2-weighted images in the subcortical white matter of both occipital lobes (arrow), in the left frontal lobe (arrow), and in the right basitemporal cortex. Nodular areas of subependymal enhancement were shown in the inferior aspect of the left and right lateral ventricles on contrast-enhanced T1-weighted images (arrows).
AJKD
QUIZ PAGE ANSWERS (continued)
What is the diagnosis? This patient had renal angiomyolipomas, cortical tuber, and subependymal nodules. A definitive diagnosis of tuberous sclerosis complex (TSC) requires 2 of the following major features: focal angiofibromas, periungual fibroma, shagreen patch, multiple retinal nodular hamartomas, cortical tuber, subependymal nodule, subependymal giant cell astrocytoma, cardiac rhabdomyoma, lymphangiomyomatosis, and/or renal angiomyolipoma. The symptom triad of TSC consists of seizures, adenoma sebaceum (facial angiofibroma), and mental retardation. However, not all patients have this classic triad. Half have normal intelligence, and 25% do not have seizures. It is an autosomal dominant disease associated with at least 2 separate chromosomes (TSC1, found on chromosome 9, and TSC2, on chromosome 16). TSC is thought to result from sporadic mutation in the majority of patients because most patients have no family history of the disease. It is important to distinguish an expanding angiomyolipoma from a renal cell carcinoma. Usually, the high fat content of the angiomyolipoma will allow it to be distinguished easily by using ultrasonography, computed tomography, or MRI. Difficulties arise in trying to distinguish a renal cell carcinoma from an angiomyolipoma with low fat content. Because renal cell carcinomas are rare, a solid lesion on imaging with a low fat content is more likely to be an angiomyolipoma. Fine-needle biopsy may be useful to distinguish the 2 lesions, but can give a false diagnosis of cancer. An expert should interpret the biopsy specimen by using a stain for HMB-45. In this case, the area in the superior pole of the right kidney was compatible with the diagnosis of angiomyolipoma. End-stage renal disease is rare in patients with TSC, but contributes to premature mortality. At present, there are no clear prognostic factors to determine which individuals are at greatest risk for developing end-stage renal disease. Importantly, it may be possible to delay or even prevent end-stage renal disease in some patients by undertaking a more conservative form of management, such as embolization, rather than nephrectomy in the earlier stages of disease.
Final diagnosis: Tuberous sclerosis complex Case provided by Antonio Granata, MD, and Adalberto Sessa, MD, Department of Nephrology and Dialysis, Catania and Vimercate, Italy.
If you have an interesting case you would like to submit for consideration, please go to http://ajkd.edmgr.com to do so.
QUIZ PAGE ANSWERS NOVEMBER 2004
A 57-year-old woman presented with renal failure (serum creatinine, 4.8 mg/dL [424 mol/L]), anemia (hematocrit, 25%), microhematuria, and severe hypertension. She had no history of seizures or mental retardation. She had no skin lesions on examination.
Figure 33C.
What do you observe on MRI of the patient’s abdomen?
Axial, contrast-enhanced, T1-weighted MRI of the abdomen showed increased kidney volume with multiple angiomyolipomas. There also was edema in the superior pole of the right kidney (arrow). Contrast-enhanced MRI of the brain was done.
Figure 33D.
What do you observe on MRI of the patient’s brain?
MRI of the brain revealed ill-defined areas of increased signal intensity on T2-weighted images in the subcortical white matter of both occipital lobes (arrow), in the left frontal lobe (arrow), and in the right basitemporal cortex. Nodular areas of subependymal enhancement were shown in the inferior aspect of the left and right lateral ventricles on contrast-enhanced T1-weighted images (arrows).
AJKD
QUIZ PAGE ANSWERS (continued)
What is the diagnosis? This patient had renal angiomyolipomas, cortical tuber, and subependymal nodules. A definitive diagnosis of tuberous sclerosis complex (TSC) requires 2 of the following major features: focal angiofibromas, periungual fibroma, shagreen patch, multiple retinal nodular hamartomas, cortical tuber, subependymal nodule, subependymal giant cell astrocytoma, cardiac rhabdomyoma, lymphangiomyomatosis, and/or renal angiomyolipoma. The symptom triad of TSC consists of seizures, adenoma sebaceum (facial angiofibroma), and mental retardation. However, not all patients have this classic triad. Half have normal intelligence, and 25% do not have seizures. It is an autosomal dominant disease associated with at least 2 separate chromosomes (TSC1, found on chromosome 9, and TSC2, on chromosome 16). TSC is thought to result from sporadic mutation in the majority of patients because most patients have no family history of the disease. It is important to distinguish an expanding angiomyolipoma from a renal cell carcinoma. Usually, the high fat content of the angiomyolipoma will allow it to be distinguished easily by using ultrasonography, computed tomography, or MRI. Difficulties arise in trying to distinguish a renal cell carcinoma from an angiomyolipoma with low fat content. Because renal cell carcinomas are rare, a solid lesion on imaging with a low fat content is more likely to be an angiomyolipoma. Fine-needle biopsy may be useful to distinguish the 2 lesions, but can give a false diagnosis of cancer. An expert should interpret the biopsy specimen by using a stain for HMB-45. In this case, the area in the superior pole of the right kidney was compatible with the diagnosis of angiomyolipoma. End-stage renal disease is rare in patients with TSC, but contributes to premature mortality. At present, there are no clear prognostic factors to determine which individuals are at greatest risk for developing end-stage renal disease. Importantly, it may be possible to delay or even prevent end-stage renal disease in some patients by undertaking a more conservative form of management, such as embolization, rather than nephrectomy in the earlier stages of disease.
Final diagnosis: Tuberous sclerosis complex Case provided by Antonio Granata, MD, and Adalberto Sessa, MD, Department of Nephrology and Dialysis, Catania and Vimercate, Italy.
If you have an interesting case you would like to submit for consideration, please go to http://ajkd.edmgr.com to do so.