<unk> , also known as<unk>  or PEC tumour, is a family of mesenchymal tumours consisting of<unk><unk> <unk> s (PECs). These are rare tumours that can occur in any part of the human body. The<unk>  type from which these tumours originate remains unknown. Normally, no<unk> <unk> <unk> s exist; the name refers to the characteristics of the tumour when examined under the microscope. Establishing the malignant potential of these tumours remains challenging although criteria have been suggested; some<unk> s display malignant features whereas others can cautiously be labeled as having 'uncertain malignant potential'. The most common tumours in the<unk>  family are renal angiomyolipoma and pulmonary lymphangioleiomyomatosis, both of which are more common in patients with tuberous sclerosis complex. The genes responsible for this multi-system genetic disease have also been implicated in other<unk> s. Many<unk>  types shows a female predominance in the sex ratio.
Perivascular epithelioid cell tumour
Aggressive angiomyxoma
Sclerosing epithelioid fibrosarcoma
Multinucleate cell angiohistiocytoma
Solid pseudopapillary tumour
Littoral cell angioma
Cavernous hemangioma
Aponeurotic fibroma