Diagnostic immunohistochemistry through Rosai-coloured glasses

Area of Science:

• Pathology
• Immunohistochemistry
• Surgical Pathology

Background:

• Immunohistochemistry (IHC) has significantly advanced diagnostic surgical pathology over three decades.
• Early foundational observations were crucial for assessing the risks and opportunities of IHC.
• Current practices heavily rely on these initial assessments, integrating IHC with histomorphology.

Observation:

• This review focuses on Dr. Juan Rosai's profound contributions to immunohistochemistry.
• Dr. Rosai's work transcends simple molecular-to-morphology linkage, identifying novel patterns in form and diaminobenzidine staining.
• His insights are particularly noted in the immunohistochemistry of thyroid and thymic neoplasia.

Findings:

• Dr. Rosai's mastery of detail and pattern recognition defined the diagnostic power of IHC.
• His approach integrates early morphological masters' work with novel IHC observations.
• His mentorship has significantly shaped academic surgical pathology.

Implications:

• Understanding Dr. Rosai's perspective offers insights into the evolution and future of diagnostic pathology.
• His contributions emphasize IHC as a companion, not a replacement, for traditional histomorphologic evaluation.
• This review provides a lens through which to appreciate the diagnostic power derived from combining morphology and immunohistochemistry.