Head & Neck Squamous Carcinoma: Artifacts, Challenges, and Controversies. Agenda

Transcription

1 Head & Neck Squamous Carcinoma: Artifacts, Challenges, and Controversies Jennifer L. Hunt, MD, MEd Aubrey J. Hough Jr, MD, Endowed Professor of Pathology Chair of Pathology and Laboratory Medicine University of Arkansas for Medical Sciences 1 Agenda Precursor lesions Conventional squamous carcinoma Lymph node dissections Sentinel lymph nodes 2 1

2 General Reactions Metaplasia Hyperplasia Ulceration and inflammation Keratosis Neoplasia Dysplasia Carcinoma 5 Normal Epithelium 6 2

3 Dysplasia Continuum Normal Mild Dysplasia Moderate Dysplasia Severe Dysplasia 7 Squamous Dysplasia Architectural features Organization Maturation Mitotic activity 8 Normal Organization 3

4 Normal Maturation Abnormal Mitoses Squamous Dysplasia Cytologic features Hyperchromasia Higher N:C ratio (basaloid) Nuclear membrane irregularities 12 4

5 Abnormal Cytology Reactive Atypia Dysplasia Normal Reactive Mild dysplasia Moderate dysplasia 15Reactive Atypia 15 5

6 Grading Dysplasia Usually a three-tiered system Mild, moderate, severe dysplasia Low grade, intermediate, high grade Mild, moderate and severe atypia 16 Grading Terminology 17 Dysplasia Continuum Normal Mild Dysplasia Moderate Dysplasia Severe Dysplasia 18 6

7 Mild dysplasia 19 Moderate dysplasia Severe dysplasia 7

8 Mild-moderate dysplasia 22 Moderate to severe dysplasia Moderate to severe dysplasia 8

9 Low Grade Atypia Inflammatory atypia vs. mild dysplasia Look for hints that it might not be dysplastic Inflammation Ulceration or ulcer debris Organisms Metaplasia Tangential sectioning 25 Inflammatory Atypia Hyperplastic Candidiasis 9

10 Hyperplastic Candidiasis Carcinoma After Dysplasia 30% 25% 20% 15% 10% 5% 0% Negative Mild Moderate Severe Barnes, L. Head & Neck Pathology 29 Squamous Cell Carcinoma Histologic Subtypes Conventional Grading T N M staging

11 Well Differentiated SCCA Poorly Differentiated SCCA Moderately Differentiated SCCA 11

12 Prognostic Factors Perineural invasion Angiolymphatic invasion Tumor size or depth Lymph node metastasis

13 Invasion Tumor that has breached the basement membrane Access to lymphatics Potential to metastasize 37 Superficial invasion Depth of Invasion 39 13

14 Metastases Regional lymph nodes Size of node Location (ipsilateral vs. contralateral) Extracapsular extension Purpose of Node Dissections To gather information Treatment planning Staging Prognostication For treatment Debulking 42 14

15 Treating the N0 Neck If risk of metastasis is >20% If high risk factors present Perineural invasion Angiolymphatic invasion Deep invasion Not differentiation and mitotic index 43 Empiric risk in cn0 Neck Location Epiglottis 15% Vocal Cord 15% Floor of mouth 25% Tonsil 36% Tongue Base 55% Oral Tongue 60% Pyriform sinus 65% Occult Metastasis 44 Head and Neck Cancer Elective neck dissection Over-treatment for many (>75%) Therapeutic for few (<25%) Morbidity of neck dissection

16 Morbidity Nerve damage Disfiguration and edema Infection Hematoma Theory of SLN Theory of SLN Afferent lymphatics Efferent lymphatics 16

17 Benefits of SLN Limited procedure Decreased morbidity Focused pathologic analysis 49 Maximal Benefit of SLN Staging relies on nodal status Risk of metastasis low Staged procedures are feasible Drainage patterns are consistent t 50 History of SLN Penile Carcinoma (1977) Melanoma (1992) Breast Carcinoma (1993)

18 Radiation Exposure Issues Storage containers (shielded) Specimen transport Training Labeling Waste disposal > 3 days of storage 52 Frozen Section Risk False negative & false positive Sampling Frozen section artifact Tissue waste Benefit Immediate completion for positive

19 Data on Frozen Section Tumor type Frozen Cytology section smear Sensitivity Sensitivity Breast 59% - 78% 57% Macro- mets >99% >90% Melanoma 38% - 47% 38% - 46% HNSCC 93%? 55 Frozen Section Analysis 56 Frozen Section Analysis 57 19

20 Experiment Lymph node 1 Pre-frozen weight: 279 mg Post-frozen weight: 220 mg (-21%) Lymph node 2 Pre-frozen weight: 623 mg Post-frozen weight: 354 mg (-43%)

21 Head and Neck SLN Balance for intraoperative assessment Detect macro-metastases Preserve micro-metastases 61 Optimal Final Work-up Levels How many? What frequency? Stains How many? Which? 62 Sampling Error 63 21

22 Sampling Error 64 Diminishing Returns 0.25 mm metastasis = 23 sections 1.8 mm metastasis = 3 sections FS Thomsen J Oral Pathol Med, 34:65, Optimal Work-up ~2-3 mm HE CK HE CK HE C K HE 66 22

23 67 67 Maximal Benefit in SLN Staging relies on nodal status Risk of metastasis low Staged procedures are feasible Drainage patterns are consistent? Arguments for SLN Helps to identify unusual drainage Significant upstaging of cn0 necks Allows for focused pathology analysis

24 Arguments against SLN Morbidity is already low Less reliable after radiation Skip metastases Increased cost and time Micrometastases Incidence is high (20-30% of cn0) Controversial clinical significance Regional recurrence may be higher May behave similar to N0 population Summary Precursor lesions Conventional squamous carcinoma Lymph node dissections Sentinel lymph nodes 72 24