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Zorluk: ZorPathology and Biopsy Interpretation

A 37-year-old man is evaluated for a palpable, non-tender nodule in the right anterior neck, discovered incidentally during a routine physical examination. He reports no dysphagia, hoarseness, or systemic symptoms. His serum thyroid-stimulating hormone (TSH) level is 1.8μU/mL1.8 \mu\text{U/mL} (normal: 0.4−4.0μU/mL0.4-4.0 \mu\text{U/mL}). A neck ultrasound reveals a 1.8 cm1.8\text{ cm} solid, hypoechoic nodule in the right thyroid lobe with irregular margins and punctate microcalcifications. A fine-needle aspiration (FNA) biopsy of the nodule is performed to establish a definitive diagnosis. Which of the following specific cytologic features, if identified on the aspiration specimen, would definitively establish a diagnosis of papillary thyroid carcinoma in this patient? (Select all that apply)

  1. Intranuclear cytoplasmic inclusions (pseudoinclusions)Cevap
  2. Longitudinal nuclear grooves (coffee bean nuclei)Cevap
  3. C
    Predominance of microfollicles with scant or absent colloid
  4. D
    Extracellular amyloid deposits displaying apple-green birefringence
  5. E
    Sheets of cells with abundant, granular, eosinophilic cytoplasm

Cevap

The correct diagnostic features are intranuclear cytoplasmic inclusions (pseudoinclusions) and longitudinal nuclear grooves.
Papillary thyroid carcinoma (PTC) is uniquely characterized by defining nuclear atypia that can be definitively identified on cytologic smears from a fine-needle aspiration. The pathognomonic findings required to confirm this diagnosis include enlarged, overlapping nuclei with cleared or empty-appearing chromatin (optically clear or 'Orphan Annie eye' nuclei), longitudinal nuclear grooves that give the nuclei a 'coffee bean' appearance, and distinct intranuclear cytoplasmic pseudoinclusions (invaginations of the cytoplasm into the nucleus). Identifying these specific features firmly establishes the diagnosis and guides subsequent surgical management.

Adım Adım Çözüm

1
Analyze the clinical and sonographic presentation.
The patient is a euthyroid man with a thyroid nodule showing highly suspicious ultrasound features for malignancy (solid, hypoechoic, irregular margins, microcalcifications).
Identifying the pre-test probability guides the interpretation of the fine-needle aspiration (FNA) results.
2
Determine the diagnostic capabilities of FNA for this pathology.
FNA is highly accurate for diagnosing papillary thyroid carcinoma (PTC) based purely on distinctive nuclear architecture.
Unlike follicular carcinoma, which requires histologic evaluation of the tumor capsule, PTC can be definitively diagnosed on cytology alone.
3
Identify the pathognomonic cytologic features of papillary thyroid carcinoma.
The defining features are nuclear: enlarged, optically clear nuclei ('Orphan Annie eyes'), intranuclear pseudoinclusions, and longitudinal nuclear grooves.
Selecting the options that match these specific histologic criteria confirms the diagnosis of PTC.

Anahtar Kavram

Fine-needle aspiration (FNA) cytology can definitively diagnose papillary thyroid carcinoma through the identification of characteristic nuclear atypia, specifically intranuclear pseudoinclusions, longitudinal nuclear grooves, and optically clear chromatin.
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Pathology and Biopsy Interpretation

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