Adequacy Criteria for Cytology Specimens

Mahra Nourbakhsh, MD, PhDResident Physician, PGY-3Anatomical Pathology

What is an adequate sample?

Disappointing and Confusing!!

• Technique (FNA, Brushing, Washing, Exfoliation, etc.)

• Operator (Clinician, Surgeon, Radiologist, Pathologist)

• Organ• Type of lesion (Solid, Cystic, Solid/Cystic)

• Pathology: (Non/Neoplastic, Malignant, Benign, inflammatory)

• Complexity of the pathology (Tumor with dual differentiation, carcinosarcoma, warthine tumor, etc.)

• Preparation, processing, staining• Patient’s condition (age, gender, history, clinical

findings)

There is no simple answer

False Negative & False Positive

Representative Sample

Normal Lesion

• Webster’s Dictionary: sufficient in quality and/or quantity to satisfy one’s needs.

• Bethesda System: Appropriate labeling and identifying information; Relevant clinical information; Adequate numbers (a compilation from the literature) of well-preserved and well-visualized representative component cells

• My approach to adequacy: When there is discordance in clinical, radiologic and cytology findings, the adequacy of the specimen is questionable.

What is an adequate sample?

Uterine Cervix

• A consensus on adequacy of cervical smear has been reached however the adequacy should still be considered case by case.

• Variable:1. Obscuring Element2. Minimum Squamous Cellularity3. Presence of Transformational Zone

(absence does not automatically indicates unsatisfactory specimen)

Uterine Cervix Obscuring Elements

•Elements:– Blood– Inflammation– Necrotic artifacts

•If covers more than 75% of epithelial cells unsat

Uterine CervixMinimum Squamous Cellularity

•Liquid Base– At least 5000 squamous cells– Metaplastic squamous cell are acceptable– Endocervical and Endometrial cells are not

included.

•Conventional– At least 8000-12000 squamous cells– Metaplastic squamous cell are acceptable– Endocervical and Endometrial cells are not

included.

Uterine CervixPresence of T Zone

•T-Zone:– At least 10 well-preserved endocervical or

squamous metaplastic cells singly or in cluster

•Absence of T-Zone does not automatically classifies the specimen as unsatisfactory.

•Report if T-zone present or absent.

Uterine Cervix

35F TAH 2°to a benign condition

Estimated cells of 5000-10000

Hysterectomy

Uterine Cervix

56F TAH 2°to Endometrial CA Estimated cells of 5000-10000

Hysterectomy

Uterine Cervix

56F with pelvic radiation Estimated cells of 5000-10000

Hysterectomy

Uterine Cervix

46F with recent chemotherapy Estimated cells of 5000-10000

Hysterectomy

Uterine CervixDoes reduction of cellularity from 8000 to 2000 is wise in post chemotherapy, post pelvic radiation or hysterectomy?

Lu Ch, et. Al. Cancer Cytopathol. 2010;118 (6):474-81

•7059 pap, 1361 had Hx of pelvic radiotherapy, chemotherapy and hysterectomy.

•Results:

•No increase in false-negative rate•Hysterectomy does not significantly correlates with unsatisfactory Pap

Unsat Criteria <8000 <2000Post Radiotherapy 17.9% 7.6%

Post Chemotherapy 19.6% 6%

Respiratory Tract (Sputum)

• Guideline of Pap Society of Cytopathology Task Force

Mod Path. 1999; 12 (4): 427-436

1. Must contain alveolar macrophages2. No numerical cut point for macrophages,

but should be easily identifiable3. Should be large enough to prepare at least

2-4 slides. 4. Sensitivity to diagnose malignancy increase

from 42% with a single specimen to 91% with five specimen.

Respiratory Tract (washing and brushing)

• Guideline of Pap Society of Cytopathology Task Force

Mod Path. 1999; 12 (4): 427-436

1. Large number of (not exactly defined), well-preserved, optimally stained ciliated bronchial epithelial cells and macrophages.

2. Should not be heavily contaminated with oral squamous cells or saprophytes

3. Absence of obscuring elements.

Respiratory Tract (BAL)• Guideline of Pap Society of Cytopathology Task

ForceMod Path. 1999; 12 (4): 427-436

1. >5% of ciliated or squamous epithelial cells contamination of distal airways.

2. Chamberlain et.al criteria of inadequacy:Chamberline DW, et. Al. Acta Cytol 1987;31:599-605

• Less than 10 alveolar mac/ 10 hpf• Less than 25 alveolar mac/10hpf and one of the

followings:– Excessive epithelial cells with degenerative features or

exceeding number of macs– Mucopurulent exudate of PMN

• Numerous obscuring RBC• Degenerative changes or artifact obscuring cell

identity

Respiratory Tract (FNA)

• Guideline of Pap Society of Cytopathology Task Force

Mod Path. 1999; 12 (4): 427-436

1. Complex issue2. No universally acceptable criteria in the

absence of abnormality.3. Depends on procedure, operator skills and

location and size of the lesion. 4. The findings are insufficient to account for

the lesion5. Use non-diagnostic rather than Unsat

Respiratory Tract • 65 M smoker, 5 cm speculated mass, BAL

Too Much Text

Urine and Bladder

• Usefulness of the specimen to diagnose or broach the suspicion of urothelial carcinoma.

• Is determined by the interplay of: 1. Collection type2. Cellularity3. Volume4. Cytomorphological findings

Urine and Bladder

• Limited publication on the role and and specific qualifiers of collection type, cellularity, and volume.

• Adequacy algorithm based on Paris system recommendation:

1. The communication between volume, collection type and cellularity.

2. Guide for individual labs in validating appropriate cut-offs for their own practice settings

3. Frame the future investigations dealing with adequacy of urine specimen

Urine and Bladder

CellularityCollection Type

Volume

Urine and Bladder: Cellularity

Instrumental Urinary Specimen1.Sat: 20 well-preserved, well-visualized. Urothelial cells per 10 high-power fields.2.Sat but limited by low cellularity: 10-20 cells3.Unsat: <10 cells

Prather J, Arville B, Chatt G, et al. J Am Soc Cytopathol. 2015;4:57-62

•1322 urothelial cells (10 per 10 hpfs) for diagnosis of atypical urothelial cells and above.

Prather J, et. al. J Am Soc Cytopathol. 2013; 2: S24-S25

1.2644 urothelial cells (20 per 10 hpfs) in the absence of atypical cells or higher to increase the positive predictive value of this test.

Prather J, Arville B, Chatt G, et al. J Am Soc Cytopathol. 2015;4:57-62

Urine and Bladder: Cellularity

Voided Urine Specimen

1.No paper in literature review investigating the cellularity required for adequacy in voided urine specimen.

2.However two studies suggest cell counts for surveillance but are older studies (>80 urothelial cells/hpf?!).

Morse N, et. al. Acta Cytol 1974: 18:312–315Murphy WM, et. al. J Urol 1981:126:320–322.

Urine and Bladder: Volume• At least 30 ml of urine is required in voided

urine samples.VandenBussche CJ, et. al. Cancer Cytopathol. 2016;124:174-180

1. Indication of voided urine cytology were not provided.

2. SurePath method.

• The Paris system recommendation shows two microscope-dependent nodes precede volume in the adequacy algorithm:

1. finding of atypical, suspicious, or malignant cells2. an adequate number of benign urothelial cells

Fluids (Pleural, Pericardial, Peritoneal)

• Adequacy have no role in providing procurement information.

• Adequacy have a role in identifying processing problem.

• In the absence of abnormality or acellular fluid, no criteria has been indicated for adequacy.

Crothers, BA. Et al. Arch Pathol Lab Med. 2009 Nov;133(11):1743-56

Peritoneal Wash

• In the absence of abnormal cells presence of mesothelial cells is recommended for reporting a specimen adequate.

McGowan L. et. Al. Obstet. Gynecol. 1989;73:136-137

• No consensus is reached for adequacy of washes.

CSF

• Adequacy have no role in providing procurement information. It is based on how much the lesion exfoliates.

• No consensus has reached

My dog shed

GI Tract (FNA)• An adequate is one that explain the

clinical/endoscopic findings.

• It is reasonable to consider a FNA adequate if there is sufficient cellularity to suggest limited DDX or explain the clinical/radiologic findings.

• Scant cellularity, obscuring elements, poorly preserved samples are the reasons for unsatisfactory aspirates

•

GI Tract (Brushing)

• No consensus is reached regarding adequacy.

• An adequate brushing is one with 6-10 well-visualized and well-preserved epithelial cell groups (at least 6 cells/cluster).

• Too few cells, poor preservation, degenerated cells, obscuring elements render the specimen unsatisfactory

Moody Dr. CAP Today. August 2003, pp 68-70

Breast

• Two opposite views toward the adequacy

• An epithelial cell cluster (ECC) cut off number for adequacy

• Non cellular features such as type of the lesion instead of ECC cut off number

Breast

• Study #1: 4455 FNA, 51 false negative in MD Anderson Cancer Institute from 1985-1995.

Boerner S., and Sneige N. Cancer 1998; 84: pp. 344-348

– Criteria: 6 ECCs on all slides for a sample to be classified as adequate,

– Results: 50% of the false-negative was avoided.

presence ≥ 10 intact bipolar cells per 10 medium-power fields (×200),

Breast• Study #2: 1779 FNA, 21 false negative

in Duke University Medical Center (1992-1995) and UCLA Center for the Health Sciences (1984-1990).

Boerner S., and Sneige N. Cancer 1998; 84: pp. 344-348

– Criteria: 6 ECCs or >10 bipolar cells in each of medium power field (X200) on all slides for a sample to be classified as adequate,

– Results: False negative rate 1.5% and unsat ratio of 20.2%.

Layfield L.J., Mooney E.E. et. al. Cancer 1997; 81: pp. 16-21

Breast• F32 with no FHx of breast malignancy with a Cystic Lesion

at 10 O’clock, measuring 3.2 cm in largest dimensionpresence ≥ 10 intact bipolar cells per 10 medium-power fields (×200),

Breast• F52 with a Solid mass at 7 O’clock, measuring 1.8 cm in

largest dimensionpresence ≥ 10 intact bipolar cells per 10 medium-power fields (×200)

Breast (conclusion)• No consensus reached.

• For suspected epithelial lesion, 6 epithelial cell cluster of 5-10 cells each reduces the false negativity.

• For non-epithelial lesion no minimal cell group is proposed.

• Use of triple test is highly recommended.

• No consensus reached for nipple discharge cytology

Thyroid • Minimum six group of well preserved , well

visualized follicular cells

• Each group contains a minimum of 10 cells.

• Preferably all six groups are on same slide

• Fewer follicular cell groups may be accepted if there is abundance of lymphocytes, granulomas or colloid.

Thyroid

Thyroid• F43 with a cystic nodule at inferior pole of Lt.

thyroid, measuring 2.8 cm presence ≥ 10 intact bipolar cells per 10 medium-power fields (×200)

Thyroid• F39 with a cystic nodule at superior pole of Rt.

thyroid, measuring 2.9 cm presence ≥ 10 intact bipolar cells per 10 medium-power fields (×200)

Thyroid• 6 months later

Salivary Gland

• Adequacy criteria has not been established yet.

• The rate of false negative is related to type of lesion, the operator (Cytopathologist, vs. Radiologist vs. Surgeon).

• False negative results are most common with low-grade mucoepidermoid carcinoma, adenoid cystic carcinoma, and non-Hodgkin lymphoma

• False-positive diagnoses are seen with cystic lesions, particularly WT and pleomorphic adenoma (PA).

Salivary Gland• Experience of UPMC: 294 case from 1999-

2012, with FNA and then surgical specimen obtained within 6 months.

Griffith CC, et. al, AM J Clin Pathol. 2015 Jun;143(6):839-53

• Adequacy Criteria: 4 hpf (×400) of epithelial cells

• Results: 28.2% inadequacy rate, including 38.6% non-neoplastic, 43.4% benign and 18.1% malignant including one case of high grade.

• Results: Specificity for pleomorphic adenoma 98.8% but sensitivity only 58.2%

Lymph Node

• FNA of any lymph node: at least a moderate number of lymphocytes must be present.

• Well preserved, well visualized lymphocyte is required.

• Based on the location of the lymph node the adequate sample might be difficult to obtained.

Lymph Node (mediastinum)

• Rapid On-Site Evaluation of FNA and Core Needle Biopsy

Choi, SM. et. Al. Ann Thorac Surg. 2016 Feb;101(2):444-50

• Using four sequential criteria, tissue core size, the presence of malignant cell, microscopic anthracotic pigments, and LD ‡40 cells/field, the sensitivity and accuracy rates increased from 64.4% to 98.6% and from 64.7% to 97.3%, respectively.

Kidney

• Up to 30% of renal aspirates are non-diagnostic (inadequate)

• Repeat aspiration is helpful in 50% of case.

• Technical failure is number one reason for inadequacy.

• No consensus on adequacy criteria

Kidney• Analysis of Results and Diagnostic Problem in 108 FNA of Renal

Masses in Adult.Truong, LD. et. Al. Diagnostic Cytopathol; 1999;20(6):339-349

Adequacy criteria in solid lesion:• Unsat:1. soft tissue and/or normal kidney tissue only2. Blood or necrotic material only3. Technically poor4. Scant cellularity: smear contains few cells or small cluster, the nature of which

cannot determined.

• Sat:1. Large number of well-preserved, isolated or cell clusters, which allow at least

limited DDX

Kidney• Analysis of Results and Diagnostic Problem in 108

FNA of Renal Masses in Adult.Truong, LD. et. Al. Diagnostic Cytopathol; 1999;20(6):339-349

Adequacy criteria in cystic lesion:• Unsat:1. soft tissue and/or normal kidney tissue only2. Blood or necrotic material only

• Sat:1. Fluid regardless of cellularity

Kidney• Analysis of Results and Diagnostic Problem in

108 FNA of Renal Masses in Adult.Truong, LD. et. Al. Diagnostic Cytopathol; 1999;20(6):339-349

Results:

1. The rate of unsat was 16% in lesion containing solid compartment and 0% in cystic lesion

2. Only one false negative case (out of 34) judged benign while later biopsy showed malignant RCC.

Kidney• 72M with a cystic renal lesion

Kidney

Current recommendation:

•No consensus, however it is reasonable to consider a FNA adequate if there is sufficient cellularity to suggest limited DDX.

•Specimen composed exclusively macrophages (typically cystic lesion) is best reported as non-diagnostic as cystic RCC can not be ruled out.

Adrenal Gland, Ovary and Deep Solid Organs

• No Standard consensus.

• Similar to Kidney (and other deep solid organs), presence of sufficient cellularity to suggest limited DDXs.

• Scant cellularity, obscuring elements, poorly preserved samples are the reasons for unsatisfactory aspirates.

Conclusion

• There is no simple/single criteria for adequacy

• Adequacy should remain in the discretion of cytopathologists even in the organ system with a defined adequacy criteria

• Clinical, radiologic and cytopathologic findings remain the most important factors for determining adequacy criteria

Thank you!

Question/Discussion?!