Giant cell tumor of the tendon sheath (nodular synovitis) is a benign soft tissue tumor, usually affecting older women, that most often occurs in the interphalangeal joints of the fingers, wrist or knee. Malign giant cell tumor of the tendon sheath is rare.

We present a case of a 56-year-old woman presented with a slow-growing, painless mass on the anteromedial aspect of the ankle 5 year duration. Apparent rapid enlargement of the mass was observed and went under surgery. The resected tumor, measuring 50x21x28 mm.cm, was encapsulated and located on the tibialis anterior tendon sheath of the ankle.

The tumor was intracapsular and its margins was clear. We performed radioterapy. The patient was quite well at the last follow-up 12 months after wide excision. It seems likely that may expect the good outcome, superficial location and the minority of the tumor composed of malignant component. However, long-term follow-up is mandatory, due to the poor prognosis.

Although soliter lipomas are very common soft tissue tumors, osteolipomas are rare.

We present a case of a solitary osteolipoma of the inguinal region in a 37 year-old male who was referred for a inguinal mass causing pain and compression of the neurovasculer structures of the inguinal region. The computed tomography scan helped to clinch the diagnosis and histpathology confirmed it. The well- demarcated, firm tumor was excised arising adjacent to the neurovasculer structures of the inguinal region.

Osteolipomas should be kept in mind in the different diagnosis of soft tissue masses as an extremely rare benign lesion.

Echinococcal cysts are mostly found in the liver followed by the lungs, spleen, ovaries, kidneys, brain, bones and heart, but rarely elsewhere in the body. Disease can take place either directly from contact with infected dogs or indirectly from the ingestion of contaminated water or food. Skeletal disease is rare and is usually due to secondary extension after haematogenous spread of the infection.

We present a case of hydatid cyst involving superior and inferior pubic ramus and retrorectal space in a 22 years old male patient, which is not a common site for the occurrence of this disease. Total cystectomy was performed for retrorectal cyst, curettage and bone cementing was done for the bony involvement.

He was well after 1 year follow up. Diagnosis is usually difficult and MRI is a good tool for reaching diagnoses. Curettage and bone cementing can be a treatment option for decreasing bony recurrences.