Clinicopathological features of peripheral ossifying fibroma in a series of 41 patients.

Peripheral ossifying fibromas are benign mesenchymal lesions that usually arise in the anterior maxilla of young female patients. Histologically they consist of spindle cell proliferation with focal mineralisation. We reviewed 48 specimens from 41 patients and recorded the clinical data, sex, and age of the patients, site and size of the lesions, treatment, and postoperative outcome. Histologically the presence of mature, woven bone, cementum, and calcifications were evaluated and evaluated immunohistochemically. Lesions were more frequent in female patients in the third and fourth decade, and were usually in the lower maxilla and smaller than 2cm. All lesions were conservatively excised, and they relapsed in eight patients. Histopathologically, the lesions were poorly circumscribed, moderately cellular proliferations, with no discernible architectural pattern. All tumours showed some degree of mineralisation, the presence of immature bone being the most common. Immunohistochemical examination showed staining of tumoural cells for smooth muscle actin and CD68. Lesions tended to occur more commonly in female patients, but one decade later than usually reported. We found a higher recurrence rate in lesions that contained cementum-like material but without bone formation, suggesting a lack of maturation in this group. Immunohistochemical results were consistent with myofibroblastic differentiation but they added no information about the behaviour of the lesions.

Síndrome de Muir-Torre / Muir-Torre syndrome

El síndrome de Muir-Torre es una genodermatosis de herencia autonómica dominante. Se asocian múltiples tumores viscerales de bajo grado, normalmentecarcinomas colorrectales, con tumores sebáceos de la piel. Representa la expresión fenotípica del cáncer de colon familiar no asociado a poliposis.El síndrome de Muir-Torre podría ser el resultado de una mutación en los genes responsables de la reparación del ADN e inestabilidad de microsatélites.Describimos 2 casos de síndrome de Muir-Torre y mostramos el análisis inmunohistoquímico de las neoplasias sebáceas (AU)

The Muir-Torre syndrome is an autosomal dominant inherited genodermatosis associating multiple low-grade visceral tumors, namely colorectal carcinomas,with sebaceous tumors of the skin. It is a phenotypic subset of hereditary nonpolyposis colorectal cancer. The defect is thought tobe the resultof a mutation in mismatch repair genes and associated with microsatelite instability. We report two cases of Muir-Torre syndrome and show immunohistochemicalanalysis of the sebaceous neoplasm (AU)

Skull osteosarcoma: illustrated review.

A case of conventional intramedullary osteosarcoma (epithelioid subtype) with 10 years of evolution and another of high grade surface osteosarcoma of the chondroblastic type, both in the skull, gave rise to several diagnostic and therapeutic difficulties. Key points concerning the definition, classification, imaging, clinical series data and treatment options available for skull osteosarcoma are highlighted.