Surgical Pathology: The Science of Tissue Diagnosis

Surgical pathology is the cornerstone of definitive disease diagnosis. It encompasses the macroscopic and microscopic examination of tissues removed during surgery to guide patient management.

Specimen Types

• Biopsies (incisional, excisional, core needle, endoscopic)
• Resections (organ, tumor, limb)
• Lymph node dissections
• Transplant donor/recipient tissues
• Products of conception

Core Responsibilities of the Surgical Pathologist

1. Gross Examination: Describe, measure, ink margins, select representative sections.
2. Histopathology (H&E): Microscopic evaluation of cellular architecture, atypia, invasion, grade, stage.
3. Ancillary Studies:
   • Immunohistochemistry (IHC) – lineage, prognostic/predictive markers.
   • Molecular diagnostics (PCR, FISH, NGS) – actionable mutations, MSI, TMB.
   • Special stains (microorganisms, amyloid, lipids).
   • Electron microscopy (rare).
4. Intraoperative Consultation (Frozen Section): Rapid diagnosis (<20 min) to guide extent of resection, margin status, or nodal metastasis.
5. Cytology: FNA, effusions, brushings—often triaged alongside surgical specimens.
6. Reporting: Structured, synoptic reports (CAP protocols) with diagnosis, grade, stage (pTNM), margins, biomarker results, and clinical commentary.

Clinical Impact

• Determines need for adjuvant therapy (chemo, radiation, targeted).
• Guides surgical re-excision or completion surgery.
• Informs prognosis and surveillance intensity.
• Enables tumor board discussion and clinical trial eligibility.

Quality Assurance

• CAP/CLIA accreditation, proficiency testing, intradepartmental correlation, turnaround-time monitoring.
• Digital pathology and AI-assisted quantification emerging for standardization.

Surgical pathologists are "the doctors' doctors"—their diagnoses directly shape every downstream clinical decision.