Tenosynovial giant cell tumor.

Tenosynovial Giant Cell Tumor (TGCT) is a group of typically benign lesions arising from the synovium of joints, bursae and tendon sheaths. Depending on their growth pattern and clinical course, they are divided into localized and diffuse types. It is predominantly caused by a mutation in the stromal cells of the synovial membrane leading to overexpression of the colony stimulating factor 1 that recruits CSF1R-expressing cells of the mononuclear phagocyte lineage into the tumor mass.

Pigmented villonodular synovitis.

Pigmented villonodular synovitis (PVNS) is a benign disease that rarely undergoes malignant transformation. There are two types of disease: localized (nodular tenosynovitis) and di used (pigmented villonodular synovitis/tenosynovitis) with intra- or extra-articular locations. The second one is limited to synovium of the burse (PVNB) or tendon sheath (PVNTS).

[Perineural cysts].

Perineural cyst (Tarlov cyst) is a lesion in a form of fluid-filled sacks, usually located within the nerve root sheath at the posterior root of a spinal nerve, whose wall is formed by: endoneurium, peripheral nerve fibers and ganglion cells and areolar tissue. Depending on the studied population, the frequency of lesion occurence was estimated at 1.5- 13.

[Epidemiology and risk factors of hepatocellular carcinoma].

Primary liver neoplasms occurs relatively rarely in Poland. The most frequently occurring type of cancer is hepatocellular carcinoma (HCC), which globally constitutes 7% of all the occurrences of cancer. The incidence increases with age and is the highest in patients around the age of 70.