Periosteal chondroma a chondroma that develops from
periosteum or periosteal connective tissue.
Consists of small surface mass ( < 3 cm) & appears as
radiolucent oval or oblong defect on periphery of underlying cortex;
The lesion is underlined by a thin, distinct cortical reaction,
has little or no calcification. (in contrast to chondrosarcoma),
occassionally there is intralesional calcifications minimal
CT is used to demonstrate extent of cortical involvement and
identify density of cartilage.
Cartilaginous tumor that arises from surface of cortex deep to the
periosteum, producing a 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;
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, patients may complain of pain at tumor site;
often can be palpated and is nontender, hard mass, fixed to bone.
Most of these lesions present in stage 2 & require en bloc marginal
excision to prevent recurrence;
A wide excision including underlying cortex is treatment of choice,
it is important to remove entire tumor without rupturing tumor
The risk of recurrence after bloc marginal excision is < 10%.