Orthopedic Pathology

This subspecialty of pathology, also know as bone pathology, is concerned with bone diseases, arthroscopy, tendinitis, rheumatoid nodules, amputations and soft tissue tumors. SPL uses gross and microscopic findings along with the findings of in vivo radiological studies, and occasionally, specimen radiographs to diagnose diseases of the bones.

Bone and tumor diagnosis

Primary bone tumors have these characteristics:

  • Most common ages: First 30 years, during the ages of the greatest skeletal growth activity.
  • Most common locations: In the bones with the highest growth rate – distal femur and proximal tibia, (for both benign and malignant tumors).
  • Two important features of bone tumors:
    1. The ability of some to dedifferentiate (eg., enchondroma or a low-grade chondrosarcoma transforming into a high-grade sarcoma)
    2. Tendency of high-grade sarcomas to arise in damaged bone, at the sites of bone infarcts, radiation osteitis and Paget’s disease.

Secondary bone tumors:
The most frequent malignant tumors found in bone are metastatic cancers. They are much more common than primary bone tumors and are characterized by the following:

  • Most common ages: Children ten years and younger and adults over 40.
  • Most common locations: Multifocality and predilection for the hematopoietic marrow sites in the vertebrae, pelvis, ribs, cranium and proximal long bones.
  • Least common locations: Metastases to long bones distal to the elbows and knees. Small bones of the hands and feet are even more rare.