February 2003: a 53-year-old male with new onset seizures

Brain Pathol. 2003 Jul;13(3):419-20, 423.


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.

Publication types

  • Case Reports

MeSH terms

  • Bone Neoplasms / complications*
  • Bone Neoplasms / pathology
  • Bone Neoplasms / surgery
  • Corpus Callosum / pathology
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Mesenchymoma / complications
  • Mesenchymoma / pathology
  • Mesenchymoma / surgery
  • Middle Aged
  • Myocardial Infarction / physiopathology
  • Osteochondroma / complications*
  • Osteochondroma / pathology
  • Osteochondroma / surgery
  • Seizures / etiology*
  • Seizures / pathology
  • Tomography, X-Ray Computed