Surgical pathology of cranial arteritis and polymyalgia rheumatica

Area of Science:

• Vascular Pathology
• Rheumatology
• Histopathology

Background:

• Cranial arteritis is a distinctive vascular disorder with characteristic acute-stage granulomatous inflammation.
• Histological findings can mimic other conditions like Takayasu's arteritis or granulomatous angiitis.
• Temporal artery biopsies are diagnostic in many cases but can be negative in over a third of patients with classical symptoms.

Purpose of the Study:

• To highlight the diagnostic challenges in cranial arteritis.
• To differentiate between active/healed arteritis and normal aging changes in arteries.
• To discuss the role of temporal artery biopsies and other investigations in diagnosis.

Main Methods:

• Review of clinical and histological features of cranial arteritis.
• Analysis of temporal artery biopsy findings in relation to clinical presentation.
• Consideration of histological changes associated with aging and healed arteritis.

Main Results:

• Positive temporal artery biopsies are diagnostic for cranial arteritis.
• Negative temporal artery biopsies occur in over a third of patients, likely due to focal arterial involvement.
• Distinguishing healed arteritis from normal aging requires careful pathological assessment.
• Polymyalgia rheumatica patients show positive biopsies in 15-55% of cases; ESR is the only supportive lab finding.

Conclusions:

• Clinicopathological correlation is crucial for diagnosing cranial arteritis, especially with negative biopsies.
• Pathologists must be vigilant to avoid misinterpreting aging-related arterial changes as healed arteritis.
• Diagnosis of cranial arteritis remains challenging, with limited diagnostic tools beyond biopsy and clinical suspicion.