Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 1 / Voluminous plexiform neurofibromas of the neck region in neurofibromatosis 1

Objetivo. Presentar las características clínicas, de imagen y evolutivas de una serie de pacientes con neurofibromatosis tipo 1 que desarrollaron durante la infancia neurofibromas plexiformes voluminosos en el cuello (NFPVC). Pacientes y métodos. Nueve pacientes (cinco mujeres y cuatro varones) con edades entre 3 y 15 años en el momento del diagnóstico de los tumores, que podían extenderse también a la fosa posterior y a la zona torácica superior. El diagnóstico estuvo basado fundamentalmente en la clínica, la imagen y la histología. Resultados. Un tumor era intralaríngeo y causaba problemas respiratorios. Los otros ocho casos tenían su origen en varias raíces espinales de uno o de ambos lados y podían crecer también hacia el interior de la fosa posterior y de la región torácica en algunos pacientes, y desplazaban a las estructuras anatómicas vecinas, especialmente en tres casos, todos niñas, en las que el tumor creció hasta alcanzar gran volumen, especialmente por un lado, parándose el crecimiento entre los 11 y 12 años y no volviendo a crecer más tarde. Conclusiones. Los NFPVC son tumores histológicamente benignos. La extirpación es necesaria cuando están localizados en la laringe por los problemas respiratorios que causan, pero no en los de las otras regiones, pese a que el voluminoso tamaño que alcanzan en algunos casos puede causar exagerados desplazamientos de las estructuras vecinas. El estudio de nuestra serie parece indicar que al menos los tumores extralaríngeos sólo crecen hasta los 11-12 años. Puede ser recomendable retrasar la cirugía tanto como sea posible si no existe sintomatología aguda que la haga necesaria (AU)

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. Nine patients (five females and four males) who were diagnosed as VPNFN at ages between 3 and 15 years. The VPNFN widespread to the posterior fossa or the upper thoracic region in some cases. The diagnosis was based on the clinical, imaging and histological findings. Results. One of the tumors was intralaryngeal and caused respiratory difficulties. The other eight patients had the origin of the tumor in several spinal roots of one or both sides and could growth to the posterior fossa and to the upper thoracic region in some cases with displacement of the surrounding organs, especially in three patients, all girls, in whom the tumor reached a voluminous size on one side, that was observed only until 10 to 11 years when the growth ceased. Conclusions. The VPNFN are histologically benign tumors. Those located in the larynx must be removed because of therespiratory problems, but it is not necessary in cases with other locations despite the voluminous size that can reach in some patients with great displacement of the surrounding organs. The analysis of the results of our series may demonstrate that al least the extralaryngeal tumors only grow to 11-12 years of age. This possibility may make recommendable to retard the surgical treatment as much as possible in cases that it is not necessary (AU)

[Voluminous plexiform neurofibromas of the neck region in neurofibromatosis 1]. / Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 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. Nine patients (five females and four males) who were diagnosed as VPNFN at ages between 3 and 15 years. The VPNFN widespread to the posterior fossa or the upper thoracic region in some cases. The diagnosis was based on the clinical, imaging and histological findings. RESULTS. One of the tumors was intralaryngeal and caused respiratory difficulties. The other eight patients had the origin of the tumor in several spinal roots of one or both sides and could growth to the posterior fossa and to the upper thoracic region in some cases with displacement of the surrounding organs, especially in three patients, all girls, in whom the tumor reached a voluminous size on one side, that was observed only until 10 to 11 years when the growth ceased. CONCLUSIONS. The VPNFN are histologically benign tumors. Those located in the larynx must be removed because of the respiratory problems, but it is not necessary in cases with other locations despite the voluminous size that can reach in some patients with great displacement of the surrounding organs. The analysis of the results of our series may demonstrate that al least the extralaryngeal tumors only grow to 11-12 years of age. This possibility may make recommendable to retard the surgical treatment as much as possible in cases that it is not necessary.

TITLE: Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 1.Objetivo. Presentar las caracteristicas clinicas, de imagen y evolutivas de una serie de pacientes con neurofibromatosis tipo 1 que desarrollaron durante la infancia neurofibromas plexiformes voluminosos en el cuello (NFPVC). Pacientes y metodos. Nueve pacientes (cinco mujeres y cuatro varones) con edades entre 3 y 15 años en el momento del diagnostico de los tumores, que podian extenderse tambien a la fosa posterior y a la zona toracica superior. El diagnostico estuvo basado fundamentalmente en la clinica, la imagen y la histologia. Resultados. Un tumor era intralaringeo y causaba problemas respiratorios. Los otros ocho casos tenian su origen en varias raices espinales de uno o de ambos lados y podian crecer tambien hacia el interior de la fosa posterior y de la region toracica en algunos pacientes, y desplazaban a las estructuras anatomicas vecinas, especialmente en tres casos, todos niñas, en las que el tumor crecio hasta alcanzar gran volumen, especialmente por un lado, parandose el crecimiento entre los 11 y 12 años y no volviendo a crecer mas tarde. Conclusiones. Los NFPVC son tumores histologicamente benignos. La extirpacion es necesaria cuando estan localizados en la laringe por los problemas respiratorios que causan, pero no en los de las otras regiones, pese a que el voluminoso tamaño que alcanzan en algunos casos puede causar exagerados desplazamientos de las estructuras vecinas. El estudio de nuestra serie parece indicar que al menos los tumores extralaringeos solo crecen hasta los 11-12 años. Puede ser recomendable retrasar la cirugia tanto como sea posible si no existe sintomatologia aguda que la haga necesaria.

Carcinoma mioepitelial de partes blandas sin reordenamiento del gen EWSR1 y mal pronóstico. Presentación de un caso / Soft tissue myoepithelial carcinoma without EWSR1 gene rearrangement and poor outcome. A case report

Los carcinomas mioepiteliales de partes blandas (STMM), afectan a las extremidades o cinturas de pacientes jóvenes y evolucionan agresivamente. Muestran una marcada atipia y bordes infiltrantes y su pronóstico empeora con el reordenamiento del gen EWSR1, presente en el 45% de los casos. Presentamos el caso de un varón de 26 años al que se le extirpó un STMM situado en la cadera derecha, compuesto por cordones y nidos sólidos de células atípicas rodeadas de un estroma mixoide-hialino, sin diferenciación ductal. Expresaban citoqueratinas, EMA, S100 y calponina. La hibridación in situ fluorescente (FISH) no reveló reordenamientos del gen EWSR1. Tras recibir cuidados paliativos, el paciente murió por múltiples metástasis a los 18 meses del diagnóstico. Se trata de un caso de STMM sin reordenamiento del gen EWRS1 pero inusualmente agresivo(AU)

Soft tissue myoepithelial carcinomas (STMM) are clinically aggressive tumors that arise in the extremities and limb girdles of young patients. Histologically, they show moderate to severe atypia and infiltrative margins. EWSR1-gene rearrangements are present in 45% of cases and are associated with increased malignancy. A large mass in the right hip of a 26-year-old male that had been surgically removed showed strands of cells embedded in a hyalin-myxoid matrix without ductal differentiation. Cells expressed cytokeratins, EMA, S-100 protein and calponin. STMM was diagnosed. Although the tumor did not have an EWSR1 gene rearrangement, it behaved aggressively and the patient died from multiple metastases 18 months after diagnosis(AU)

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). MPNSTs can show different degrees of malignancy, but overall spinal MTTs are high-grade lesions. We report the exceptional instance of a spinal low-grade MTT in a 39-year-old man treated with total surgical removal followed by local radiation therapy. Histological low grade was based on the lack of necrosis, a low grade of atypia, a low mitotic rate and a Ki-67 labelling index <25%. After 18 months of follow-up the patient is alive with no evidence of disease. A thorough review of the literature yielded 57 well-documented spinal MPNSTs. Ten of them corresponded to MTTs, but none showed low-grade features. An analysis of the clinical, radiological and treatment data was performed to identify factors that might influence the outcome. Overall the 18-month survival rate was 45% but dropped to 0% in the subgroup of spinal MTTs. Besides, a size exceeding 2 cm, extra-spinal extension, association with neurofibromatosis and subtotal removal were all related to a worse outcome. In conclusion, spinal MTTs generally exhibit a more aggressive behavior than conventional MPNSTs. The occurrence of a spinal low-grade MTT with a better prognosis should also be recognized.

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. Of these 24 patients, 19 were initially diagnosed with adynamic bone lesion (ABL). After 1 year, 12 still had ABL; the other 7 had changed to high turnover bone lesion (HTBL). Another 5 patients were initially diagnosed with HTBL. Among these, 4 still had HTBL at 1 year; 1 had changed to ABL. In patients who changed to HTBL from ABL, serum albumin had increased to 4.2 +/- 0.3 g/dL at month 12 from 3.7 +/- 0.4 g/dL at baseline (p < 0.05). In patients who still had ABL, serum albumin did not change. Additionally, the percentage increase in serum albumin over the study was higher in HTBL patients than in ABL patients (0.1408 +/- 0.139 g/dL vs. -0.0076 +/- 0.113 g/dL, p = 0.009). A lower likelihood of diabetes (p = 0.033) and a higher serum albumin [area under the curve: 0.822; 95% confidence interval (CI): 0.651 to 0.993] identified a HTBL diagnosis at 12 months. Older age increased the probability of changing to ABL (OR: 1.2935; 95% CI: 1.03 to 1.67; p= 0.02). Bone lesions can change over time, and this change is associated with age, diabetes, and serum albumin. A change to HTBL was associated with improvement in serum albumin. Protein status is possibly a factor influencing bone lesion outcome.

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. Specific induction of DAX1 by EWS/FLI1 was confirmed in two independent cell systems with inducible expression of EWS/FLI1. We also analyzed the expression of DAX1 in Ewing tumors and derived cell lines, as well as in other nonrelated small round cell tumors. DAX1 was expressed in all Ewing tumor specimens analyzed, and in seven out of eight Ewing tumor cell lines, but not in any neuroblastoma or embryonal rhabdomyosarcoma. Furthermore, silencing of EWS/FLI1 by RNA interference in a Ewing tumor cell line markedly reduced the levels of DAX1 mRNA and protein, confirming that DAX1 up-regulation is dependent upon EWS/FLI1 expression. The high levels of DAX1 found in Ewing tumors and its potent transcriptional repressor activity suggest that the oncogenic effect of EWS/FLI1 may be mediated, at least in part, by the up-regulation of DAX1 expression.

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: 1.75 mmol/l). METHODS: Forty-four PD patients were randomized to receive LCD or continue on SCD for a period of 12 months. Bone biopsies were taken at baseline and at 12 months. Biochemical data and treatment were evaluated every 3 months. RESULTS: Twenty-four patients completed the study. In the SCD group (n = 10), nine out of the 10 patients were initially diagnosed with adynamic bone lesion (ABL). After 1 year, six continued having ABL and three patients moved to high-turnover bone lesion (HTBL). The other patient, initially diagnosed with HTBL, changed to ABL. In the LCD group (n = 14), 10 patients were initially diagnosed with ABL. At 1 year, six of them continued having ABL and four patients changed to HTBL. Four patients were initially diagnosed with HTBL and did not change. Comparison between LCD and SCD groups showed an increase in serum parathyroid hormone (PTH) levels starting at month 3 and a higher intake of calcium salts in the former group (P<0.01). Serum calcium, phosphate levels and bone histological outcome did not differ between the two groups. CONCLUSIONS: LCD use for 1 year was associated with an increase in PTH levels, but did not lead to histological changes different from those observed in SCD group. The LCD solution allowed a higher oral intake of calcium salts with a satisfactory control of the serum Calcium-Phosphorus product.

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. Roentgenograms of short and long bones showed symmetrical, well-defined, non-expansile cystic lesions. Bone biopsy found a yellow lipid-like substance in the osteolytic lesions and histopathological studies were non-specific. Neuropsychiatric examination, including cranial computerized tomography (CT), was found to be normal. According to clinical, analytical, radiological and histological findings ML was the diagnosis. No previous cases of ML have been reported in our country as we review the literature concerning this disease.

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. Both CT and MR imaging revealed an extradural mass contiguous with the posteroinferior endplate of the T4 vertebral body. This case indicates that radiation-induced osteochondroma should be considered in the differential diagnosis of patients with symptoms of myelopathy or nerve root compression and a history of radiation therapy involving the spine in childhood.