A practical diagnostic approach to solid/trabecular nodules in the thyroid

Area of Science:

• Endocrinology
• Pathology
• Oncology

Background:

• Thyroid nodules with non-follicular-non-papillary structures, particularly solid/trabecular patterns, are common.
• These patterns present diagnostic challenges due to a wide range of differential diagnoses, including adenomas, papillary carcinoma variants, hyalinizing trabecular tumors, and paragangliomas.

Purpose of the Study:

• To address the diagnostic difficulties in classifying thyroid nodules with a predominant solid/trabecular pattern.
• To propose an effective diagnostic strategy utilizing immunohistochemistry.

Main Methods:

• Review of diagnostic hallmarks for various entities presenting with solid/trabecular patterns in thyroid nodules.
• Recommendation of a stepwise immunohistochemical marker panel, starting with thyroglobulin and calcitonin.
• Development of a diagnostic algorithm based on morphology, clinical setting, and immunohistochemical results.

Main Results:

• Morphological assessment alone is often insufficient for accurate diagnosis of solid/trabecular thyroid tumors.
• A panel of immunohistochemical markers is crucial for precise subtyping.
• The proposed algorithm aids in differentiating common and rare tumors within this category.

Conclusions:

• Accurate typing of solid/trabecular thyroid nodules requires a combination of morphological evaluation and targeted immunohistochemistry.
• The recommended diagnostic algorithm can improve diagnostic accuracy and patient management.