Rozpoznanie i leczenie nowotworów typu angiomyolipoma (AML)

Abstract

Angiomyolipoma (AML) is the most commonly occurring tumour from the PEComa family (PEC tumours; perivascular epithelioid cell tumours), a rare group of neoplasms of mesenchymal origin. AML may occur sporadically or in the course of tuberous sclerosis and lymphangioleiomyomatosis. The sporadic type form is the most common subtype of benign kidney tumours and is four times more frequent in women. Kid ney tumours of the angiomyolipoma type are most commonly detected by chance during an abdominal cavity ultrasound scan, during which they are visible as hyperechogenic tumours, and in most cases they are not a diagnostic problem. AML growth is slow, and complications are rare. The main AML complication can be bleeding to the retroperitoneal space or to the pelvicalyceal system. The typical method of AML care is active surveillance (AS). Asymptomatic tumours with a diameter under 4 cm require control by ultrasound examination every 12 months whereas tumours with a diameter of less than 2 cm are considered not to require control ultrasounds. AML with a diameter of over 4 cm require more frequent ultrasound scans — every six months. The size of the tumour, the presence of symptoms (e.g. pain in a tumour projection, haematuria), planned pregnancy, or suspicion of a malignant tumour are critical in therapeutic decisions. Active treatment options include: embolisation, ablation techniques, nephron-sparing surgery (NSS), and radical nephrectomy. In adult patients with tuberous sclerosis, who require treatment but do not require rapid surgical treatment, everolimus is used. In the case of AML, initially doses of 1 × 10 mg per day should be used (an appropriate dose decrease is required in the case of liver insufficiency), and subsequently treatment may be individualised after determining the lowest effective dose with acceptable adverse effects. A rare epithelioid variety of AML (EAML) shows the potential for a malignant course. The basis of EAML treatment is radical resection, ensuring a high percentage of cures. For non-resectable EAML, chemotherapy, mTOR inhibitors, and VEGFR inhibitors (pazopanib, apatinib) are used, but objective responses have been described only in a very small percentage of patients