[Voluminous plexiform neurofibromas of the neck region in neurofibromatosis 1].

AIM. To present the clinic, imaging and evolutive characteristics of a series of patients with neurofibromatosis 1 with voluminous plexiform neurofibromas in the neck (VPNFN) during childhood. PATIENTS AND METHODS.

Low-grade malignant triton tumor in the lumbar spine: a rare variant of malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation.

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon type of sarcoma that arises from peripheral nerve sheaths and rarely involves the spinal roots. The origin of this tumor is thought to be Schwann cells or pluripotent cells of the neural crest. The subgroup of tumors in which malignant Schwann cells coexist with malignant rhabdomyoblasts is termed malignant triton tumor (MTT).

Osteoblastoma of the temporal bone.

Benign osteoblastoma is an uncommon primary tumor of the bone. Any area of the skeleton may be affected by this tumor, but its occurrence in the temporal bone and middle ear is extremely rare. Clinical symptoms are nonspecific, even in the middle ear, and the diagnosis is often difficult in spite a complete physical and radiological examination.

Long bone florid reactive periostitis ossificans: a case in the distal femur mimicking osteosarcoma.

Florid reactive periostitis ossificans is a well-known benign lesion classically described in hands and feet which histopathological features can lead to a misdiagnosis of osteosarcoma. To the best of our knowledge, there is only one previous report of this lesion in a long bone. In this study we report a case of florid reactive periostitis ossificans located in the distal metaphysis of the left femur that histologically mimicked an osteosarcoma and discuss the differential diagnosis between these two entities to warn about a diagnostic pitfall.

Serum albumin levels, an additional factor implicated in hyperparathyroidism outcome in peritoneal dialysis: a prospective study with paired bone biopsies.

Renal osteodystrophy encompasses several histologic subtypes, all of which can undergo change over time. In peritoneal dialysis (PD) patients, we studied bone histology and the factors influencing any changes over 1 year In 44 PD patients, we collected two paired bone biopsies (at baseline and after 12 months) and biochemical and treatment data (at baseline and every 3 months). Of the 44 original patients, 24 completed the study.

The orphan nuclear receptor DAX1 is up-regulated by the EWS/FLI1 oncoprotein and is highly expressed in Ewing tumors.

The Ewing family of tumors harbors chromosomal translocations that join the N-terminal region of the EWS gene with the C-terminal region of several transcription factors of the ETS family, mainly FLI1, resulting in chimeric transcription factors that play a pivotal role in the pathogenesis of Ewing tumors. To identify downstream targets of the EWS/FLI1 fusion protein, we established 293 cells expressing constitutively either the chimeric EWS/FLI1 or wild type FLI1 proteins and used cDNA arrays to identify genes differentially regulated by EWS/FLI1. DAX1 (NR0B1), an unusual orphan nuclear receptor involved in gonadal development, sex determination and steroidogenesis, showed a consistent up-regulation by EWS/FLI1 oncoprotein, but not by wild type FLI1.

Low vs standard calcium dialysate in peritoneal dialysis: differences in treatment, biochemistry and bone histomorphometry. A randomized multicentre study.

Background: In patients undergoing peritoneal dialysis (PD), low-calcium dialysate (LCD) has been proposed as the first choice for a better control of renal osteodystrophy. Our aim was to compare the effects on bone metabolism of LCD (calcium: 1.25 mmol/l) with that of a standard calcium dialysate (SCD; calcium: 1.

Membranous lipodystrophy. Case report and review of the literature.

Membranous lipodystrophy (ML) is a rare hereditary disorder of adipose tissue characterized by polycystic bone lesions and progressive dementia. We describe the case of a 36-year-old woman with mechanical bone pain. Routine laboratory analyses revealed only a type IV hyperlipoproteinemia and hyperexcretion of urinary calcium.

Radiation-induced osteochondroma of the T4 vertebra causing spinal cord compression.

A case of a radiation-induced osteochondroma arising from the vertebral body of T4 in an 18-year-old man is reported. The patient presented with a history of progressive left lower extremity weakness. At 7 years of age, he had undergone resection of a cerebellar medulloblastoma and received adjunctive craniospinal irradiation and systemic chemotherapy.