King Edward Memorial Hospital - Departments: Radiology

Radiology

Case of the Month

Case No. :	48
Month :	December
Year :	2002
Contributor :	Dr. Nilesh Gupta

Other Cases

Radiological Investigations

Discussion

Differential Diagnosis

CLINICAL PRESENTATION :

This is a case of a 38-year-old lady who presented with a swelling on the right side of the abdomen and right flank pain since two months. She also has vomiting after meals and loss of appetite.

On examination, a 7x5x6 cms lump was palpable in the right lumbar region; it was mildly tender and was non ballotable. She had malar rash with erythematous nodular lesions over the nose (Fig.1).

Fig.1

RADIOLOGICAL INVESTIGATIONS:

An ultrasonographic examiniation of the abdomen (Figs. 2,3,4,5) showed heterogenously


Fig.2

Fig.3	Fig.4

enhancing lesions predominantly intensely echogenic cortical lesions in the both the kidneys with acoustic shadowing . These lesions had few areas of hypoechogenecity suggesting hemorrahge and necrosis.

Doppler usg showed abnormal dilated, tortuous interlobular renal vessels.

Fig.5

Plain and contrast enhanced CT scans abdomen (Figs.6-10) showed illdefined heterogenously


Fig.6	Fig.7

enhancing lesions in both the kidneys with few areas of hypodensities of HU of fats (-20), and muscles (+20 ) . On contrast injection, abnormally enhancing irregular vessels were noted.


Fig.8

Fig.9	Fig.10

Hence a diagnosis of bilateral angiomyolipoma was made. In view of its association with tuberous sclerosis and the clinical features in this patient, CT scan of the brain was also performed, and it showed the classical sub ependymal nodules and cortical tubers. (Figs.11-14)


Fig.11	Fig.12

Fig.13	Fig.14

DISCUSSION:

Angiomyolipoma is a benign tumour arising from mesenchymal elements of the kidney like blood vessels, muscles and mature fat. Histologically, it consists of adult type of adipose tissue, pleomorphic hyperplastic smoothy muscle. The intimal layer in the vessels is absent.

Usually, patients are asymptomatic or present late in the 3rd to the 4th decades of life with pain, lump, hematuria, and occasionally shock due to spontaneous retroperitoneal hemorrhage from pseudoaneurysms. These complications occur mainly in tumours which are over 4cms in diameter.

Angiomyolipomas of the kindney have an association with tuberous sclerosis. In such patients, the renal lesions manifest earlier in life - typically in the second and third decades. The sexual sex incidence is equal. The tumors in such cases are usually larger, multiple and bilateral with increased risk of haemorrhage.

These lesions are usually managed conservatively if the size less than 4 cms. Yearly followup is recommended. If larger, surgery (partial nephrectomy or total nephrectomy) or selective transcatheter arterial embolization, either by coil or polyvinyl alcohol or gelfoam may be performed.

DIFFERENTIAL DIAGNOSIS:

Includes liposarcoma, lipoma, renal cell carcinoma, atypical Wilm' s tumour, lipomatosis, renal infarction, oncocytoma. Liposarcomas have inhomogenous, large cystic mass with areas of hemorrhages and necrosis and occassional calcifications(12%). Renal cell carcinomas have macrolipids with excessive calcifications with an echogenecity which is the same as that of the renal sinus. Atypical Wilms tumours occurs in childhood. They are typically encapsulated with focal haemorrhages with necrosis.Lipomatosis is well defined without any element of muscle and vessels , usually in the renal sinus.