The giant cell tumor of bone (GCT) is a locally aggressive intraosseous neoplasm, with an uncertain biological behavior, constituted of giant multinuclear cells spread over tumoral tissue with a nucleus presenting the same features of the ovoid and fusiform cells forming its stroma. The local recurrence of GCT is often observed, mainly in the first three years after treatment, giving a rate of recurrence ranging in 20 to 50% of cases. Further aggravating the recurrence is the fact that after the relapse, the patient often also presents metastases in other organs.

The aim of this study was to identify and to characterize differentially expressed genes that can be used in the prognostic, treatment and understanding of this physiopathology. To identify novel genes differentially expressed in GCT, we have applied rapid subtractive hybridization (RaSH). Samples of GCT and normal tissues were obtained at Tumor Bank of Barretos Cancer Hospital. After RNA extraction and cDNA synthesis the samples were submitted to Rapid hybridization Subtraction (RaSH) methodology for subtractive libraries elaboration.

The RaSH subtractive libraries reveals the presence of 619 different clones including both normal and tumor tissues were identified. Of these, 450 in tumor sample and 169 in control tissue. Four biomarkers candidates were selected for validation: ZAK, KTN1, NEB, and ROCK1 genes, whose functions are, related to cell cycle checkpoint, transport of organelles, cytoskeletal matrix and cell adhesions. The validation of selected differentially expressed genes was performed using real time PCR. The putative molecular markers found in this work may help to find the basis for a molecular comprehension of GCT, thus improving diagnosis, treatment and outcome for patients with this tumor.

Gorham syndrome is a rare disease of unknown cause. It is characterized by the massive bone destruction associated to bone angiomatosis. It was first described by Jackson in 1838. Gorham and Stout published their initial report in the fifth decade of the last century. The diagnosis depends on the exclusion of other diseases that cause bone lysis. The treatment has no uniformity between the oncologists, and different modalities of therapeutic procedures are being used as radiotherapy, biphosphonates, interferon and surgery.

This case reports a man, 44 years old, caucasian farmer that had a progressive pain in the left groin one year ago. The pain was getting worst and migrated to the left hip. A pelvis X-ray revealed isquiatic lysis with total disappearing of the bone. The left hip presented diffuse lytic areas too. The clinical profile of the patient was good and it was discrepant when compared to the X-rays with bone destruction.The investigation was done with bone scintilography, MRI of the pelvis, computed tomography (CT) of abdomen and chest, blood analysis of PTH, calcium, phosphate, eletrophoresis of proteins, PCR, hepatic function, and two consecutive bone biopsies of the left hip and pelvis. All exams excluded metastatic or primary bone tumors. A multi-disciplinary team of clinical oncologists, endocrinologists, nephrologists excluded other neoplastic, metabolic and rare diseases as Hadju and Cheney acro-osteolysis, carpal and tarsal osteolysis, multicentric osteolysis with nephropaty, hereditary multicentric osteolysis, Joseph acro-osteolysis, Shinz acro-osteolysis, Faber disease and Winchester disease. A multidisciplinary meeting decided by the orthopaedic surgery and radiotherapy to relieve the pain and to achieve the pathological diagnosis. The girdlestone surgery was done and the histopathological analysis showed diffuse angiomatosis in the specimen, diagnosing Gorham syndrome.

Gorham syndrome diagnosis depends on a tripod: clinical exclusion of other pathologys, image investigation and histopathology diagnosis. All three characteristics are primordial to the diagnosis of this pathology and a full investigation in a multidisciplinary level is necessary.