Page 587 - Concise Pathology for Exam Preparation ( PDFDrive )

572 SECTION II Diseases of Organ Systems

Complications:
1. Draining sinus tract
2. Suppurative arthritis
3. Pathological fracture
4. Secondary ankylosis (fibrosis and fusion of joint)
5. Endocarditis
6. Squamous cell carcinoma with a chronic nonhealing ulcer (Marjolin ulcer)
Clinical features:
Fever, leucocytosis and throbbing pain over the affected region (differential diagnosis:
is Ewing sarcoma as it may have a similar clinical presentation)
X-ray:
Lytic focus surrounded by sclerosis.
Clinicomorphological variants of osteomyelitis:
Chronic osteomyelitis results from inadequate antibiotic treatment or incomplete surgi-
cal debridement. Extensive periosteal reactive bone formation associated with chronic
osteomyelitis is called involucrum.
Brodie abscess is a small devascularized osteomyelitic focus which becomes encapsulated
and surrounded by dense sclerotic reactive bone.
Sclerosing osteomyelitis of Garre typically develops in the jaw, and is associated
with extensive new bone formation that obscures many of the underlying osseous
structures.
2. Tuberculous osteomyelitis:
1–3% cases of pulmonary and extrapulmonary tuberculosis present with osseous
involvement. Age group affected is adolescents and young adults. Skeletal tuberculosis
usually presents as a solitary lesion but may be multifocal in immunodeficient state,
eg, AIDS.
Modes of spread:
• Haematogenous (from active visceral disease)
• Direct extension (from a pulmonary focus into the ribs or tracheobronchial nodes
into the vertebrae)

FIGURE 21.2 Sequestrum or dead bone showing irregular surface and ragged margins.

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