Cutaneous myositis ossificans: an appropriate descriptor for fibro-osseous lesion of the external auditory canal.

Myositis ossificans is a benign pseudosarcomatous bone-forming lesion, histologically characterized by 2 components: a spindle (myo)fibroblastic cell population and a bony component that is arranged in a "zonal" pattern. It mainly affects the deep soft tissues of limbs, but its occurrence in other unusual locations, such as abdomen, inside nerves, and the subcutaneous fat, has been reported. The existence of myositis ossificans restricted to the skin has rarely been published under the term "fibro-osseous lesion of the external auditory canal." Here, we describe an additional case in the external auditory canal, emphasizing its differential diagnosis and alerting dermatopathologists and pathologists to the possibility of encountering such lesion in this anatomic location. For purposes of unifying terms, we propose that cases similar to ours be called "cutaneous myositis ossificans" instead of fibro-osseous lesion of the external auditory canal.

Fibrodisplasia arterial

La fibrodisplasia arterial es causa poco conocida de enfermedad vascular. Presentamos un paciente que consultó por lesiones úlcero-necróticas en extremidades. La arteriografía revelaba patrón rosariforme en los vasos, los exámenes de laboratorio eran normales y la biopsia evidenció hiperplasia medial que comprometía vasos arteriales y venosos. Es el primer informe en la literatura de hiperplasia medial en arterias digitales y en vasos venosos. Resaltamos la importancia de reconocer esta patología por los diagnósticos diferenciales que plantea, en especial las vasculitis. Debemos pensar en fibrodisplasia en pacientes que consultan por episodios vasculares oclusivos, sin manifestaciones sistémicas, con exámenes de laboratorio normales y hallazgos radiológicos sugestivos.

Myositis ossificans of traumatic origin in the foot.

This case reviews a myositis ossificans of traumatic origin discovered beneath the fifth metatarsal in an adult male. Details of its anatomic appearance are illustrated with the assistance of plane film roentgenography and magnetic resonance imaging. Histologic sections are included to support the diagnosis and present characteristic cellular patterns. A review of the literature including etiology, clinical classification, and diagnostic criteria are also presented.

Ectopic ossification.

Ectopic ossification is a biologic process in which new bone is formed in tissues which normally do not ossify. Three cases of this disease are described. The literature on this subject has been extensively analysed and organized. Classification, etiology, clinical and radiological features and laboratory tests are discussed. The paper also discusses the histopathology, differential diagnosis and management of this disease.

Heterotopic bone formation after total hip arthroplasty.

Heterotopic bone formation is a common complication of total hip arthroplasty. A certain degree of heterotopic bone formation occurs in about one-half of the patients in degrees ranging from very mild to moderate involvement. The patients do not necessarily have any clinical disability; only 2 per cent of the patients developed severe heterotopic bone radiographically, and unsatisfactory functional results. There is no sex predilection for heterotopic bone formation except that the condition appears more severe in females. All ages are equally affected. The underlying disease process in the hip does not influence the occurrence of heterotopic bone. The incidence was significantly greater in patients who developed postoperative hematomas, prolonged wound drainage, or superficial infection. When surgical exposure is difficult and retraction of soft tissue aand soft tissue damage takes place, the incidence is much greater. Patients who have undergone previous surgical procedures about the hip present a greater risk in regards to development of disabling heterotopic bone formation. The etiology of heterotopic bone formation is not known. The following steps should be taken to avoid or greatly minimize the development of heterotopic bone: meticulous exposure with most careful retraction, copious irrigation with antibiotic solution, debridement of devitalized tissue prior to closure, instillation of drainage tubes, intraoperative and postoperative antibiotics, and carefully controlled postoperative anticoagulation.

Nontraumatic myositis ossificans in healthy individuals.

Myositis ossificans has been subclassified into three categories: traumatic, progressive, or those cases associated with neuromuscular and chronic disease. Four cases of myositis ossificans occurred in otherwise healthy individuals without any history of trauma. These four patients illustrate a fourth and distinct subclassification of the disease.

Pseudomalignant myositis ossificans. A pathological study of eight cases.

Eight cases of pseudomalignant myositis ossificans are presented. There was a male predominance and four patients were under 20 years of age. There was no history of trauma, but there was evidence of mild local or general inflammation with positive roentgenograms in two cases. Histologically there was active fibroblastic proliferation, appearing to develop essentially in fibrin deposits with metaplasia leading to the formation of an unusual osteoid. The newly formed mass was surrounded by bone and compressed the surrounding muscle fibers, which were either atrophic or trapped therein. The histological criteria distinguishing this disorder from other forms of myositis ossificans are discussed, and comparisons are drawn with nodular fascitis and proliferative myositis. An association with the latter was observed in one case. This nontumourous growth must be distinguished from osteogenic sarcoma of soft tissue. The differential diagnosis is based on careful histological criteria, which must be supported by clinical and radiological data.