title: February 2003: a 53-year-old male with new onset seizures.
abstract: The February COM. A 53-year-old obese man presented with new onset seizures and an MRI scan revealed a large cystic and necrotic heterogeneously enhancing left frontal mass. Craniotomy revealed a firm subdural tumor on the cortical surface that was delivered en-bloc preserving the pial planes and stripping it from the falx cerebri. The tumor consisted of multiple irregular fragments of white-tan rubbery tissue admixed with globules of bosselated, white-tan rubbery tissue and a fragment of bone. Sections of the tumor revealed mature hyaline cartilage with no atypia of the chondrocytes. There was focal mineralization and endochondral ossification. A diagnosis of intracranial mesenchymal osteochondroma was made. Osteochondroma, a benign cartilaginous neoplasm comprised of mature hyaline cartilage with focal ossification, is the most common benign bone tumor. Extraskeletal (mesenchymal) osteochondromas are known to originate from non-skeletal or non-cartilaginous tissue. Intracranial osteochondromas are uncommon, typically arising from the base of the skull. Only about 15% of intracranial osteochondromas arise supratentorially, from the dura, usually in a parafalcine frontoparietal location and some have been a component of Maffucci's syndrome and Ollier disease. Intracranial osteochondromas can occur at any age with a predilection for younger individuals. Intracranial mesenchymal osteochondromas exhibit a benign clinical course. Typically, the histomorphology resembles mature hyaline cartilage without anaplastic proliferation of chondrocytes or nuclear atypia, with a lobular arrangement of clusters of lacunae containing single chondrocytes. Transition to osteochondrosarcoma has rarely been documented.
authors.affiliation: Department of Pathology (Division of Neuropathology), University of Pittsburgh, Pa, USA.
authors.forename: Bennet I
authors.initials: BI
authors.lastname: Omalu
authors.forename: Clayton A
authors.initials: CA
authors.lastname: Wiley
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Hamilton
mesh_terms: D001859:Bone Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery; D003337:Corpus Callosum / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008637:Mesenchymoma / Q000150:complications / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology; D015831:Osteochondroma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D012640:Seizures / Q000209:etiology* / Q000473:pathology; D014057:Tomography, X-Ray Computed