- Discussion:
- cartilaginous tumor that arises from surface of cortex deep to the periosteum producing broad based cartilaginous mass that may extend into soft tissues;
- often develops after adolescence (in contrast to osteochondroma)
- persists as mass of mature cartilage w/o calcification or ossification (in contrast to chondrosarcoma);
- tumor is does not infiltrate the adjacent soft tissue but may increase in size;
- Location:
- over 50% of these tumors are found in lateral cortex of proximal humerus just proximal to insertion of deltoid muscle;
- other lesions are evenly dispersed thru out the long bones;
- Clinical Manifestation:
- pts may complain of pain at tumor site;
- often can be palpated & is nontender, hard mass, fixed to bone;
- Radiographs:
- consists of small surface mass ( < 3 cm) & appears as radiolucent oval or oblong defect on periphery of underlying cortex;
- lesion is underlined by a thin, distinct cortical reaction.
- has little or no calcification but may have spicules of mineralization radiating from the cortex, providing a "sunburst" appearance (in contrast to chondrosarcoma);
- occassionally there is intralesional calcifications & minimal periosteal rxn;
- radiographic diff dx:
- osteochondroma in younger patients;
- juxtacortical chondrosarcoma;
- parosteal and periosteal osteosarcomas;
- CT scan:
- CT is used to demonstrate extent of cortical involvement and identify density of cartilage;
- Histology:
- low power view shows lobulated hyaline masses that are well circumscribed;
- lesion is usually hypocellular and well circumscribed;
- isolated areas of increased cellularity may be seen;
- lesion is composed of benign cartilage but it looks more active than an enchondroma;
- this lesion may be confused with chondrosarcoma;
- Treatment:
- most of these lesions present in stage 2 & require en bloc marginal excision to prevent recurrence;
- wide excision including underlying cortex is treatment of choice;
- its important to remove entire tumor w/o rupturing tumor capsule;
- risk of recurrence after bloc marginal excision is < 10%, & more aggressive excision or adjuvant chemo & XRT are not indicated
Tumors: Periosteal Chondroma. A Report of Ten Cases and Review of the Literature.