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Zorluk: OrtaPathology and Biopsy Interpretation

A 68-year-old woman is evaluated in the clinic for new-onset, severe right-sided headaches, scalp tenderness, and pain in her jaw when chewing over the past two weeks. Laboratory studies show an erythrocyte sedimentation rate of 85 mm/h. She is immediately started on high-dose oral prednisone. Four days later, a biopsy of the right temporal artery is performed.

The pathologist's report describes the following findings:
- Marked intimal hyperplasia causing luminal narrowing
- A transmural mixed inflammatory infiltrate composed primarily of lymphocytes and macrophages
- Extensive fragmentation of the internal elastic lamina
- No multinucleated giant cells are identified across multiple serial sections

Based on these histopathologic findings, which of the following is the most accurate diagnostic interpretation?

  1. The findings confirm giant cell arteritis despite the absence of multinucleated giant cells.Cevap
  2. B
    The absence of multinucleated giant cells effectively excludes the diagnosis of giant cell arteritis.
  3. C
    The changes are characteristic of normal age-related arteriosclerosis, ruling out an active vasculitis.
  4. D
    The histopathologic features indicate polyarteritis nodosa rather than giant cell arteritis.
  5. E
    The biopsy is nondiagnostic because prior corticosteroid therapy has masked the defining histologic features.

Cevap

The findings confirm giant cell arteritis despite the absence of multinucleated giant cells.
The correct answer identifies that the biopsy findings are diagnostic of giant cell arteritis (GCA) even though multinucleated giant cells are absent. GCA is characterized histologically by a transmural inflammatory infiltrate (predominantly mononuclear cells such as lymphocytes and macrophages), intimal hyperplasia leading to luminal narrowing, and fragmentation of the internal elastic lamina. While multinucleated giant cells are a classic finding, they are only present in 50% to 75% of cases. Therefore, their absence does not exclude the diagnosis when other defining histopathologic features are present. Furthermore, treatment with corticosteroids should be initiated immediately when GCA is suspected to prevent irreversible vision loss; temporal artery biopsy can still yield diagnostic findings for up to 2 to 4 weeks after the initiation of steroid therapy.

Adım Adım Çözüm

1
Analyze the patient's clinical presentation.
The patient has classic symptoms of giant cell arteritis (GCA), including new-onset headache, scalp tenderness, jaw claudication, and an elevated ESR.
Establishing the pre-test probability is essential before interpreting the biopsy results.
2
Evaluate the histopathologic biopsy findings.
The biopsy shows intimal hyperplasia, transmural mononuclear inflammation, and internal elastic lamina fragmentation, without multinucleated giant cells.
The pathologist's description provides the definitive microscopic evidence for or against the diagnosis.
3
Correlate biopsy findings with the diagnostic criteria for GCA.
Transmural inflammation and elastic lamina fragmentation are pathognomonic for GCA. Multinucleated giant cells are only seen in about 50% to 75% of cases and are not required for diagnosis.
Recognizing that the absence of a classically named feature (giant cells) does not exclude the disease is critical for accurate biopsy interpretation.

Anahtar Kavram

Giant cell arteritis is diagnosed histologically by transmural mononuclear inflammation of the artery with intimal hyperplasia and internal elastic lamina fragmentation. Multinucleated giant cells are only present in up to half of cases and are not strictly required for the diagnosis.
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Pathology and Biopsy Interpretation

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