Morphologic Clues and Pitfalls for High Grade Lesions in Cervical Cytology

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1 Morphologic Clues and Pitfalls for High Grade Lesions in Cervical Cytology Ritu Nayar, MD Northwestern University, Feinberg School of Medicine Chicago, IL, USA

2 Disclosures Editor, Cervical Cytology Bethesda Atlas, 2 nd and 3 rd editions No royalties accepted by editors and authors in order to keep the price low Co-Chair CAP/ASCCP LAST Project for Standardized Histopathology Reporting Terminology for HPV Associated Anogenital Lesions No royalties or conflicts

3 WHY TBS 2014 /3rd Edition of Atlas? Significant changes in cervical cancer prevention New screening and management guidelines Changes in histopathology terminology Increasing uptake of HPV vaccination Primary HPV screening; Pap as diagnostic triage New data and technology Additional experience with LBP over last 10 yrs New data: Endometrial cells, Anal cytology, Biomarkers, Automation, Risk assessment

4 BETHESDA 2014 UPDATE 3 rd Edition of the Cervical Cytology Bethesda Atlas 2015 Print and ebook

5 Squamous Epithelial Lesions 40/100 anogenital INFECTION LSIL (CIN1) PRECANCER HSIL (CIN2/3) Wright T, Schiffman M. NEJM 2003

6 Bethesda 2014: Squamous Epithelial Abnormalities Atypical Squamous Cells (ASC) ASC-US, ASC-H Low Grade Squamous Intraepithelial Lesion (LSIL) High Grade Squamous Intraepithelial Lesion (HSIL) HSIL, r/o invasion Squamous cell carcinoma

7 Cervical Cytology Screening Median (50 th percentile) Reporting Rates Category LBP Conv ASC-US 5.1% 2.6% LSIL 2.7% 1.0% HSIL 0.4% 0.2% AGC 0.2% 0.1% CAP LAP Checklist 2016

8 Squamous Reference Nuclei 35 Normal intermediate cell (X) Reactive ( X) 50 Normal squamous metaplastic cell ASC-US (2.5-3X) >105 LSIL (>/= 3X)

9 HSIL Nuclear size, shape and chromasia varies Nuclear membranes frequently irregular, grooves can be seen LBP Conv

10 HSIL Overall cell size varies from cells similar to those in LSIL to small basal-type cells N:C ratio higher than in LSIL

11 HSIL Cytoplasm is variable Densely metaplastic Distinguish from immature squamous metaplasia OR Immature/ lacy and delicate Distinguish from histiocytes

12 Bethesda 2014: HSIL Patterns 1. Classic-single cell, syncytial clusters 2. Involving glands 3. In atrophy 4. Stripped nucleus 5. EM stroma-like/repair-like 6. Hypochromatic 7. Keratinizing

13 (1) HSIL: Classic Pattern A. Single cell Isolated cells or small groups High N:C ratio Irregular nuclear membrane Granular chromatin, variable chromasia No nucleoli LBP Conv

14 HSIL Patterns Small cells/ few cell groups Problematic with regard to localizing as well as categorizing the cells. SP Higher false negatives Look in empty spaces between cells in LBP TP

15 Benign Mimickers of HSIL single cell pattern 1. Squamous immature and mature metaplasia 2. Normal endocervical/endometrial cells 3. Inflammatory cells (histiocytes, lymphocytes) 4. Decidua/Repair 5. IUD Change

16 Squamous metaplasia Squamous metaplastic cells can cause concern for HSIL Conv N:C ratio of <50%, smooth nuclear contours, and even distribution of chromatin favor benign squamous metaplasia Conv Degeneration can cause nuclei to be hyperchromatic/ wrinkled LBP

17 HSIL versus Endocervical Cell Chromatin nuclear membrane abnormal Denser cytoplasm +/- Nucleolus EC

18 Microglandular hyperplasia LBP Microglandular Hyperplasia- endocervical cells 32 yr/f, Day 12. On oral contraceptives (conventional smear)

19 Histiocytes HSIL Conv Conv LBP LBP

20 Lymphocytic (Follicular) Cervicitis Polymorphous population of lymphocytes, with or without tingible body macrophages LBP- lymphocytes maybe in clusters or scattered in the background LBP LBP LBP

21 HSIL Smaller cells N/C ratio higher Hyperchromatic nuclei with coarse chromatin Decidual cells HSIL Gestational cells- 6 week PP Pap!

22 Intrauterine Device Effect Irritated, exfoliated endocervical cells Isolated cells more often HSIL mimickers Smudgy chromatin, degenerated May be associated with Actinomyces

23 (1) HSIL: Classic Pattern B. Syncytial clusters Hyperchromatic crowded groups Loss of polarity Lack of cytoplasmic boundaries Nuclear features similar to single cell pattern HSIL Nucleoli usually inconspicuous Conv LBP

24 Differential Diagnosis of Syncytial Pattern of HSIL Hyperchromatic Cell Clusters HCG HCG Definition: 3D aggregates Crowded cells Dark nuclei HSIL HSIL extending into endocervical glands Endocervical neoplasia (AIS) Benign endocervical cells Lower uterine segment/ endometrial Atrophy

25 (2) HSIL involving endocervical glands Useful to suggest HSIL 1. Flattening of cells at the periphery of the cluster giving a smooth round border 2. Loss of cell polarity within center of cluster 3. Presence of isolated squamous cells in background 4. Lack of specific AIS features

26 HSIL involving endocervical glands Peripheral palisading of EC cells with nuclear pseudostratification can occur HSIL Pay attention to nuclear chromatin HSIL is not as coarsely granular as AIS AIS AIS

27 (3) HSIL in Atrophy Atrophy Hyperchromatic crowded groups of small parabasal cells Bland chromatin Smooth nuclear contours Conv Parabasals HSIL HSIL Cells show a syncytial arrangement Focusing in different planes allows one to better distinguish them from the parabasal cells in the background LBP HSIL

28 Transitional metaplasia HSIL Nuclear grooves Nuclear grooves

29 Isolated atypical cells without any corresponding SIL. Chromatin often pyknotic/degenerative. Atypia in atrophy HSIL look-alike

30 (4) HSIL: Stripped Nucleus Pattern Individual stripped nuclei Small groups of stripped nuclei loosely aggregated Nuclei may be enlarged, irregular, and hyperchromatic Nuclei may be bland LBP Conv

31 HSIL Stripped Nucleus Pattern vs. Cytolysis HSIL Cytolysis Cytolysis: The size, chromatin are similar to intact intermediate cell nuclei. Lack of nuclear features of HSIL

32 HSIL: Stripped Nucleus Pattern versus Naked Nuclei in Atrophy Naked nuclei in atrophic Paps Reported under NILM in TBS Also called Small blue cells (SBC) Small grape-like clusters and as single nuclei Little to no cytoplasm LBP Nuclei hyperchromatic, usually size of intermediate squamous cell nuclei Nucleoli inconspicuous DDx: HSIL, Small cell ca, Lymphoid Conv

33 (5) HSIL: Hypochromatic Pattern Pale staining nuclei with fine chromatin granularity Otherwise abnormal nucleienlarged, irregular nuclear contours TP Can be mistaken for endocervical cells Artifact or degenerative? Most associated with ThinPrep?Methanol fixation

34 Herpes simplex Nuclei have ground glass appearance and may have eosinophilic intra-nuclear inclusions Typically 3 M s Margination Multinucleation Molding Mimic Degenerated endocervical cells

35 (6) HSIL EM stroma/repair-like Bloody background simulating menses Small tightly packed groups of cells Small isolated cells with high N:C ratio Prominent spindle cell component Cytoplasm spindles from group margins Nucleoli +/- Pattern seen in litigation cases Look for classic HSIL

36 (7) HSIL: Keratinizing Isolated or tightly packed 3-D groups Can have moderate to abundant cytoplasm Eosinophilic, glassy Dense, opaque nuclei small to large with irregularity Anisonucleosis-caudate, tadpole, elongate, whorled May be difficult to grade

37 Bethesda 2014 LSIL with some features suggestive of the presence of HSIL Presented to the Internet Open comment BB Decision to limit terminology to LSIL/HSIL Biology does not support an intermediate category Management guidelines use LSIL/HSIL LSIL-H creates a de facto 3 tier system Expected poor reproducibility Expected overutilization May lead to clinician confusion

38 How To Report Equivocal SIL in TBS 2014 In occasional equivocal cases options are ASC-H + LSIL when definite LSIL in background (preferred) SIL of uncertain grade with comment as to why Should occur in only a small % of cases. ASC-H + LSIL Keratinizing SIL. Comment:..

39 Atypical Squamous Cells, Cannot Exclude HSIL (ASC-H) Cytologic changes suggestive of HSIL, but lacking criteria for definitive interpretation ASC-H does not reflect a single biological entity; mixture of CIN 2/3 and its mimics ASC-H is not a reproducible interpretation Interobserver agreement poor Comprises about 5-10% of ASC

40 ASC-H: Pattern 1- Rare single cells Pre-menopausal woman, conventional smear Perimenopausal, h/o LSIL LBP

41 ASC-H: Pattern 2 Crowded sheet pattern 100 % of diagnoses NLIM E-M ASC- US ASC-H LSIL HSIL SCC AEC AEmC AIS IAC Diagnosis

42 ASC-H Pattern 3 Few cells with high N/C ratio % of diagnoses NLIM E-M ASC- US ASC-H LSIL HSIL SCC AEC AEmC AIS IAC Diagnosis

43 ASC-H: Pattern 4 Keratinized cells 50 year old postmenopausal woman, prior abnormal cytology

44 ASC-H: Common Overcalls Endocervical cells

45 Bethesda 2014 Reporting Glandular Epithelial Abnormalities Atypical Specify if endocervical, endometrial or glandular cells Specify endocervical and glandular cells with qualifier favor neoplastic or NOS or add a comment Endocervical adenocarcinoma in situ (AIS) Adenocarcinoma Endocervical, endometrial, extrauterine, NOS

46 Reference Nuclei Endocervical and Endometrial 35 Normal intermediate cell 35 Benign endometrial cell Normal /Reactive endocervical cell Endocervical AIS

47 Normal Endocervical Cells Mean nuclear area of the normal endocervical cell is 54 +/-8 microns Nucleus round to ovalnumber and location depends on functional state of the cell Prone to cytoplasmic lysis- naked nuclei Presence of small nucleoli/ chromocenters useful Reactive cells can be scary

48 EC Adenocarcinoma in Situ Cytology Hyperchromatic crowded groups Increased nucleus to cytoplasmic ratio Nuclei large (75 um2) Even chromatin with coarse granularity Micronucleoli Rosettes, feathering Strips with pseudostratification Mitoses, apoptotic bodies

49 Endocervical AIS: rosettes, large nuclei with coarse granular chromatin, pseudostratification and some feathering (Conventional smear)

50 Conventional ThinPrep ThinPrep ThinPrep Endocervical AIS ThinPrep

51 Conventional ThinPrep Endocervical AIS Surepath ThinPrep

52

53 Endometrioid AIS Smaller cells than usual type AIS Absence of EM stroma and stromal fragments Most commonly missed AIS

54 HSIL vs. AIS Features HSIL AIS Strips & Rosettes Absent Present Gland forms Absent Present Feathering Absent Present Polarity Lost Maintain Nu Shape Round/irreg Oval/cigar Chromatin Fine/Coarse Coarse/granular Even Even Cytoplasm Dense Dense/mucin Background Isolated cells Rare/absent

55 Co-Existing HSIL and AIS

56 Invasive EC Adenoca Abundant abnormal cells Many features of AIS Macronucleoli Cytoplasm finely vacuolated Necrotic tumor diathesis may be present In LBP >3-D clusters more Isolated cells seen Chromatin more open Clinging diathesis

57 Cytologic Mimickers of AIS/AGC 1) Abundant normal endocervical cells 2) Repair 3) Endocervical polyps 4) Intrauterine device effect 5) Tubal metaplasia 6) Directly sampled endometrium 7) Squamous neoplasia 8) Metastatic tumors

58 Benign/Reactive/Abundant Sampling device effect Voracity of sampling Hyperchromatic crowded groups EC cells may be pleomorphic Repair and adenocarcinoma Endocervical Cells

59 EC ADENOCA BENIGN EC

60 Reactive Endocervical Cells AEC associated with biopsy site

61 Endocervical Repair Repair can involve squamous or columnar epithelium A sheet like pattern with distinct cytoplasmic outlines, streaming polarity, and typical mitosis distinguish it from high-grade lesions Nucleoli often seen LBP s : rounder cell groups, less streaming, nucleoli are more prominent LBP

62 Endocervical Polyps Common Bleeding, surface ulceration EC proliferation - abundant cellularity - HCG s Reactive changes- enlargement, nucleoli, mitoses Inflammation- repair Degeneration- abnormal chromatin Can mimic EC or EM neoplasia

63 Reactive cellular changes associated with IUD Glandular cells singly or in clusters Resemble abnormal endometrium - 3 dimensional, vacuoles - enlarged nuclei, Cytoplasm variable, often signet ring cells Nuclear degeneration Nucleoli + Calcifications +/-

64 TUBAL METAPLASIA Conventional Pap (60X) ADENOCARCINOMA IN SITU (AIS)-LBP (40X)

65 Tubal Metaplasia(TM): Troublesome Cytologic Features Architectural and cytologic Features that mimic AIS Enlarged nuclei Hyperchromasia Pseudostratification Rare mitosis/apoptosis Look for Cilia/ terminal bar Goblet /peg cells Round to oval nuclei Finely dispersed chromatin Washed-out nuclei Large stripped nuclei

66 Directly sampled endometrium Can mimic AIS

67 Trachelectomy-Fertility Sparing Surgery The cervix is amputated in continuity with the parametrium and upper vagina, sparing the uterus and adnexa An isthmic-vaginal junction is created; surgical margin may be at the lower uterine segment (LUS) or be endocervical F/Up is with periodic Pap tests

68 Endometrium Exfoliated Tight 3-d groups Small reniform nuclei Small nucleoli Less cytoplasm Fewer vacuoles No organoid structure Mitoses uncommon Degenerative changes Direct Sampling Tight 3-d groups or loose 2-d sheets Same Same More cytoplasm - wispy More vacuoles Tubule and gland formation Mitosis/apoptoses common Intact structure Dr David Wilbur

69 Squamous Neoplasia Mimicker May present as contoured clusters with nucleoli- Most common cause of AGC/ AEC atypia Most common with broom/brush LBP Look for Individual dysplastic squamous cells Lack of typical EC architecture

70 Atypical Endocervical/ Glandular Cells Atypical endocervical cells, favor neoplastic. F/up was AIS Atypical endocervical cells, likely derived from radiation changes Atypical endocervical cells, NOS. F/Up: AIS Atypical glandular cells, NOS OR possibly related to IUD

71 Which Cells Should You Report in the OTHER/ EMC 45 yrs TBS 2014 Category? Exfoliated Em s Directly sampled Em s LUS fragments Histiocytes

72 Bethesda 2014: Endometrial Cells: The How and When of Reporting Endometrial cells are reported in women ages 45 and greater - to increase PPV and reduce unnecessary endometrial biopsies The educational note specifies endometrial evaluation only in postmenopausal women SAMPLE REPORT: CERVICAL PAP TEST Endometrial cells are present in a woman 45 years of age. Negative for squamous intraepithelial lesion. or Endometrial cells correlate with the menstrual history provided NOTE: Endometrial cells in women 45 years or older may be associated with benign endometrium, hormonal alterations, and, less commonly, endometrial or uterine abnormalities. Endometrial evaluation is recommended in postmenopausal women.

73 AGC (Endometrial) Small groups of 5-10 cells Nuclei slightly enlarged, small nucleoli Slight hyperchromasia Ill-defined cell borders, Cytoplasm- scant, vacuoles+/-

74 Atypical Endometrial cells Criteria is primarily increased nuclear size F/Up: Hyperplasia Not further qualified as NOS/ neoplastic; difficult and poorly reproducible Causes: EM polyps, IUD, endometritis, EM hyperplasia, and EM adenocarcinoma F/Up: Adenoca Grade 1

75 Approach to TBS Category of Atypical Glandular Cells (AGC) 1. Cell Type Endocervical Glandular Endometrial Skip this step 2. Severity NOS Favor neoplastic NOS 3. Management 1. Colposcopy/biopsy/ECC+/- EMB 2. Cone/LEEP for favor neoplastic only

76 Endometrial Adenocarcinoma Cellularity lower than endocervical adenoca Cells single /small grps Intracytoplasmic vacuoles, PMNs Higher grade more easily recognized Need to differentiate from extrauterine, especially ovarian ca

77 Adenocarcinoma Endocervical versus Endometrial

78 Endocervical Endometrial Cellularity Abundant Sparse Cells Larger, columnar Smaller, rounder Groups Crowded, rosettes, feathering Nuclei Oval, elongate Round Balls, molded groups, single cells Large ( m) Coarser, dark chromatin Multiple Smaller (60-90m) Fine chromatin Single

79 Endocervical Endometrial Cytoplasm Granular, more eosinophilic, rare PMN s Vacuolated, more basophilic, PMN s common Associated lesions Squamous-HSIL Clinical risk factors Histiocytes Diathesis Granular, bloody Watery IHC CEA + Vimentin + Hormonal markers Negative ER/PR + HPV testing/ p16 IHC Positive in most Negative

80 Metastatic tumors Rare Metastatic malignancies Ovary Endometrial Breast Small cell carcinomasquamous, ER neuroendocrine Lymphoma Other- serous ca, adenoid cystic ca, colon Background clean unless there is direct extension of tumor Foreign material IHC stains Pap Serous Ovarian Breast ER

81 Bethesda 2014 Web Atlas BIRST-2: Bethesda Interobserver Reproducibility Study Self test

82 Bethesda Interobserver Reproducibility Studies Cancer Cytopathol 2007;111(1): JASC. Online March 27, 2017

83 Current Reporting Terminology HPV Associated Squamous Lesions of the Anogenital Tract BETHESDA 2014 Cervical Cytology Maintains original 1988 LAST (2012) / WHO (2014) Histopathology Terminology 2 Tiers: LSIL/HSIL 2 Tiers: LSIL/HSIL asccp.org and cap.org