Intranuclear cytoplasmic inclusions (invaginations) in thyroid aspirations. Frequency and specificity

Area of Science:

• Cytopathology
• Endocrinology
• Oncology

Background:

• Intranuclear cytoplasmic inclusions are a debated cytologic criterion for thyroid carcinoma.
• Their diagnostic utility and specificity require further investigation.

Purpose of the Study:

• To determine the frequency and specificity of intranuclear cytoplasmic inclusions in thyroid aspirates.
• To evaluate their role in the cytologic diagnosis of thyroid carcinoma.

Main Methods:

• Retrospective review of 258 consecutive thyroid aspirate samples.
• Analysis of the presence of intranuclear cytoplasmic inclusions in various thyroid lesions.

Main Results:

• Intranuclear cytoplasmic inclusions were observed in 91% of papillary adenocarcinomas.
• No inclusions were found in benign thyroid lesions or non-papillary adenocarcinomas.
• The findings suggest inclusions are specific to thyroid carcinoma, not exclusively papillary.

Conclusions:

• Intranuclear cytoplasmic inclusions are a highly specific cytologic marker for thyroid carcinoma.
• Their presence is not limited to the papillary variant, broadening their diagnostic significance.