FNAC of Breast Lesions with Special Reference to IAC Standardized Reporting and Comparative Study of Cytohistological Grading of Breast Carcinoma.

BACKGROUND: International Academy of Cytology (IAC) has established a process to produce comprehensive and standardized approach to fine-needle aspiration cytology (FNAC) reporting. They have categorized the breast lesions in C1 to C5. (C1-Insufficient material, C2-Benign, C3- Atypical, C4-Suspicious & C5-Malignant). AIMS AND
OBJECTIVES: The aim of study is to classify various breast lesions (C1 to C5) and to grade breast carcinoma on FNAC using Robinson's grading system which is then correlated with modified Bloom-Richardson grading.
MATERIALS AND METHODS: All routine FNAC for breast lump were included in the study during the period from Jan 2016 to Jan 2017. The study was conducted in the Department of pathology and lab medicine of a tertiary care hospital in central India.
RESULTS: A total 225 female patients were included in the study, with an age group ranging from 15 - 79 years, with lesions in breast were taken. C1 lesions were found in 3 cases, C2 in 186 cases, C3 in 13 cases, C4 in 4 cases, and C5 in 19 cases. Correlation of cytohistological grading was obtained in 108 cases.
CONCLUSION: Cytological categorization based on IAC structured reporting will enhance the reproducibility of reports among pathologist & clinicians. With the comparison between cytohistological nuclear grading, the cytoprognostic scores will help in evaluating the aggressiveness of tumor, predicts histological grade and prognosis. It could be a useful parameter for selecting neo-adjuvant chemotherapy. Copyright:

INTRODUCTION

Breast cancer is now the most common cancer in Indian women, having recently overtaken cervical cancer.[1] An estimated 1.5 lakh (10% of all cancers) new cases were reported in 2016 as per the data from ICMR making it the number one cancer overall.[2] The use of fine-needle aspiration cytology (FNAC) is increasing for preoperative diagnosis of breast carcinoma. Bethesda sponsored conference on uniform approach to breast FNAC had recommended that tumor grading on FNAC material should be incorporated in FNA reports for prognostication.[3]

IAC has established a comprehensive and standardized approach to categorize FNAC of breast lesions into C1-C5.[4] Structured reporting can empower the quality, clarity, and reproducibility of reports across departments, cities, countries, will assist patient management, improve breast health care, and facilitate further research.[456] Histological grading of breast carcinoma using modified Scarff–Bloom–Richardson (SBR) grading system is a widely accepted tumor grading system. Hence, in the era of neo-adjuvant chemotherapy, grading of breast carcinoma should be incorporated in FNAC reports for prognostication.[7]

AIMS AND OBJECTIVES

The purpose of present study is to analyze and categorize various breast lesions with special reference to IAC standardized reporting system along with grading the breast carcinoma on FNAC using Robinson's grading system and to assess the concordance of cytological grading with histological grading using Elston–Ellis modification of SBR grading system.

MATERIALS AND METHODS

The present study was carried out at the Department of Pathology & Lab Medicine of our institute, over a period of 1 year (January 2016 to January 2017). It was a prospective study of 225 cases carried out in patients with age range of 15 to 79 years. FNAC was done by using 10 cc syringes with 22-23G needle under all aseptic precautions. Air dried smears were stained with Giemsa stain and wet smears were stained with PAP stain. H and E stain was done for histopathology.

IAC has established a process to produce comprehensive and standardized approach to FNAC reporting. They have categorized the breast lesion into C1 to C5 (C-Code).

C1: Insufficient material

C2: Benign

C3: Atypical probably benign

C4: Suspicious, probably in situ or invasive carcinoma

C5: Malignant

All C5 cases were graded cytologically using Robinson's criteria, compared with Elston and Ellis modified Bloom–Richardson grading system.

RESULTS

We had a wide age group patient ranging from 15 years to 79 years. Most of the cases (60.5%) were in age group of 2nd and 3rd decade, with a predominance of right sided breast lesions 107 (47%) cases, followed by left side 103 (46%) cases and the bilateral 15 (7%) cases.

Out of the total 225 cases, the final cytological report was given as per the IAC coding system and had C1 in 03 (1.3%) cases, C2 in 186 (82.6%) cases, C3 in 13 (5.7%) cases [Figures 1], C4 in 04 (1.7%) cases, and C5 in 19 (8.4%) cases. Among C2 lesions, 48.3% (90) cases were fibroadenoma followed by 32.7% (61) cases of benign breast disease, inflammatory lesion 07% (13) cases, fibrocystic disease in 5.4% (10) cases, galactocele 4% (07) cases, and mastitis 2.6% (05) cases.

Figure 1

Cytosmears show cellular stromal fragment along with few scattered plump spindle cells (PAP, ×10 & ×40). C3-Atypical, Benign Phyllodes tumor

C3 lesion in our study included fibrocystic disease with mild atypia 01 case, benign fibroepithelial lesion 03 cases, fibroadenoma with atypia 05 cases, benign phyllodes tumor 03, and papillary neoplasm 01 case. C4 lesions included 4 cases of suspicious for duct carcinoma. C5 lesions being the second most common entity in our study were all ductal carcinoma.

Follow-up was available in 108 cases which included one case of benign breast lesion which was C1 (insufficient material) in cytology [Table 1]. Among the C2 lesions, follow-up was available in 74 cases, all were benign (fibroadenoma 55 cases, followed by benign breast disease 07 cases, inflammatory lesion 04 cases, granulomatous mastitis 03 cases, galactocele 2 cases, FA with fibrocystic disease/lactational change, duct ectasia included 01 case each). [Table 2] C3 (Atypical probably benign) lesions 10 out of 13 cases, histopathology follow-up was available (03 cases each of fibroadenoma and benign phyllodes tumor, 01 case each of fibroadenoma with apocrine change, complex fibroadenoma, juvenile fibroadenoma, and duct papilloma). Cytology slides of C3 follow up cases were reviewed and found that the degree of atypia among ductal epithelial cells was not much significant, presence of columnar cells, papillary fronts without nuclear atypia, lack of stromal atypia or spindle cells, squamous metaplasia along with young age of patient, and breast lump greater than 10 cm being the causes for placing the cases in to C3 [Table 3].

Table 1

Correlation between IAC grading and histopathology

IAC grading Cytology	Histopathology follow-up		No follow-up	Nonrepresentative sampling
	Benign	Malignant
C1 (03)	01	00	02	00
C2 (186)	74	00	112	00
C3 (13)	10	00	03	00
C4 (04)	00	03	00	01
C5 (19)	00	19	00	00

Table 2

Cytology-Histology correlation of C1 and C2 lesion of breast

Histopathology	IAC Grading
	C1 (3)	C2 (186)
		Inflammatory lesion (13)	FA (90)	Fibrocystic disease (10)	Galactocele (7)	Benign breast disease (61)	Mastitis (5)
Benign breast disease	1	2	-	-	-	5	-
Inflammatory lesion/Abscess	-	3	-	-	-	-	1
Necrotizing granulomatous lesion	-	1	-	-	-	-	2
Fibroadenoma	-	-	35	1	-	19	-
Galactocele	-	-	-	-	2	-	-
Duct ectasia	-	-	-	-	-	1	-
FA with Fibrocystic disease	-	-	-	1	-	-	-
FA with Lactation change	-	-	-	-	-	1	-

Table 3

Cytology-Histology correlation of C3, C4, and C5 lesions of breast

Histopathology	IAC Grading
	C3 (13)					C4 (04)	C5 (19)
	Fibro cystic disease with atypia (01)	Benign fibro-epithelial neoplasm (03)	FA with atypia (05)	Benign phyllodes tumor (03)	Papillary neoplasm (01)	Sugg. of Duct ca. (04)	Duct ca. (19)
Fibroadenoma	1	-	2	-	-	-	-
Benign phyllodes tumor	-	-	-	3	-	-	-
Complex fibroadenoma	-	-	1	-	-	-	-
FA with apocrine change	-	-	1	-	-	-	-
Juvenile fibroadenoma	-	1	-	-	-	-	-
Duct papilloma	-	-	-	-	1	-	-
Duct carcinoma	-	-	-	-	-	3	19
Negative for malignancy	-	-	-	-	-	1	-

In C4 lesions, histopathology follow-up was available for all the 04 cases (03 cases of duct carcinoma and one case was negative for malignancy). Review of C4 slides revealed limited number of atypical cells in cytology, deep seated lesion, nonrepresentative biopsy, and radiological suspicion, leading to cytohistological discordance [Table 3].

All the C5 (19 cases) lesions had follow-up; histopathological and cytological correlation was done based on Robinson's criteria. Majority of cases had a Robinson's score of two (cell dissociation in 63% cases, cell size 57.8% cases, nucleoli 47% cases, nuclear margin 57.8% cases, and chromatin condensation in 52.6% cases). However, cell uniformity cytological score was 3 in 63% cases [Tables 3 and 4]. Overall Robinson's grade for cytology was well differentiated 15.7% cases [Figure 2], moderately differentiated in 57.8% cases [Figure 3], and poorly differentiated in 26.3% cases [Figure 4].

Table 4

Cytological score of C5 cases

Robinson’s score	Cell dissociation	Cell size	Cell uniformity	Nucleoli	Nuclear margin	Nuclear chromatin
1	02 (10.5%)	01 (5.2%)	00 (00%)	05 (26.3%)	02 (10.5%)	04 (21%)
2	12 (63.1%)	11 (57.8%)	07 (36.8%)	09 (47.3%)	11 (57.8%)	10 (52.6%)
3	05 (26.3%)	07 (36.8%)	12 (63.1%)	05 (26.3%)	06 (31.5%)	05 (26.3%)

Figure 2

(a, b, c) Cytosmears showing tumor cells in cohesive clusters, mild atypia, and indistinct nucleoli (Giemsa, ×10 & ×40 and PAP, ×40)-C5, Malignant. d: Histopathology had features of Infiltrating ductal carcinoma (Grade I) (H and E, ×10)

Figure 3

(a, b) Cytosmears showing tumor cells in dissociate sheets, moderate atypia, and prominent nucleoli (Giemsa, ×40 and PAP, ×40)-C5, Malignant. c: Histopathology had features of Infiltrating ductal carcinoma (Grade II) (H and E, ×10)

Figure 4

(a, b) Cytosmears showing tumor cells in scattered singly, marked atypia, prominent nucleoli, tumor giant cells, and background necrosis (Giemsa, ×40 and PAP, ×40)-C5, Malignant. c: Histopathology had features of Infiltrating ductal carcinoma (Grade III) (H and E, ×10)

Histological grading was done using Elston and Ellis modified Bloom–Richardson grading system and we found that most of the cases were in moderately differentiated grade 58% (11 cases) followed by poorly differentiated in 26.3% (06) cases and well-differentiated in 16% (02) cases.

In our study, the concordance in C2, C3, and C4 lesion were 97% with two cases being discordant. One case each of benign fibro-epithelial lesion (C3) and suspicious for duct carcinoma (C4) showed features of juvenile fibroadenoma (young age of patient, larger size of lump) and negative for malignancy (non-representative sampling) respectively in histopathology.

Correlation of cytological grade with histological grade of C5 lesions, we found that one case out of three cases which were cytologically diagnosed as grade I was diagnosed as grade III on histopathological grading. In addition, one case diagnosed as grade II on cytological grading was found to be grade III on histopathology. Overall, cytohistological grade concordance was found to be 89% (17 cases). Only two cases had variation between cyto and histological grading; reason for discordance carcinoma (Grade I) due to subjective variation while assessing cytological features that are not included in histological grading. In addition, deep seated lesions, pauci-cellularity of smear, and technical error were the cause. The overall sensitivity and specificity in our study was 100% and 97%, respectively.

DISCUSSION

Breast cancer is the most common female cancer worldwide. It accounts for nearly a quarter (25%) of all cancers with an estimated 1.5 lakh new cancer cases diagnosed in 2016. Women from less developed regions (8,83,000 cases) have slightly a greater number of cases compared to more developed (7,94,000) regions.[12] In India, although age adjusted incidence rate of breast cancer is lower (25.8 per 100 000) than United Kingdom (95 per 100 000), mortality is at par (12.7 vs 17.1 per 100 000) with United Kingdom.[28]

Accurate diagnosis of breast cancer is made in 99% of cases by the combination of clinical examination, mammography, and simple, non-invasive, cost-effective outpatient department procedure—fine-needle aspiration cytology (FNAC). Technique of FNAC has wide applicability and utility for the tumors which are easily palpable on external examination.[89]

In developed world, core needle biopsy is the preferred procedure as compared to the practice breast FNA. On the contrary, in developing countries like India, even today, the core needle biopsy is still not practiced routinely at most of the medical centers. The treatment of breast carcinoma cases starts with the first-hand diagnosis made on FNAC. In a resource-limited country like India, FNA is preferred in comparison to core needle biopsy. The former being cheaper, less invasive, sampling of different areas of the lesion in the same sitting at no added expenses and usually fetch good results the same day.[910] Rapid onsite evaluation will reduce inadequate rates and costs to the system by reducing the need for repeat procedures and triaging cases for ancillary tests.[11] Linking cytology reporting to management algorithms will enhance the clinicians use of FNAB cytology and where appropriate core biopsy. Standardized use of cell blocks, immunohistochemistry, in situ hybridization, and other molecular tests of prognostic and diagnostic markers will improve patient care.[12]

IAC Breast Group members who attended the Yokohama International Congress of Cytology discussed regarding the use of a 3- or 5-stage coding system. IAC standardized reporting includes five categories from C1 to C5. Inadequate degree of cellularity of the epithelial cells comes under C1. This can be due to erroneous aspiration, smearing, or staining. C2 or benign is for lesions showing the characteristic pattern of different benign lesions. Usually cellular, with ductal configuration, myoepithelium, and bipolar nuclei. Inflammatory background may also be there. Smears with features of cellular crowding, pleomorphism, and discohesion, which are not seen in benign lesions, are categorized under C3 or atypical. Aspirate with features such as poor preservation, hypocellularity, or components of a benign smear, precluding the diagnosis of malignancy, are reserved for C4 or suspicious malignant category. Aspirates with strong malignant findings are categorized under C5.[456] However, there has been two areas of major debate, i.e. the definitions of “atypia” and “suspicious for malignancy.”[4131415]

In our study, 1.3% cases had inadequate aspirate and were placed in C1 category which was in concordance with studies done by Modi et al.[16] (1.36%), Sunita et al.[17] (2.9%) and Sudarat N[18] (4.9%), whereas Bajwa and Tariq[19] had a slightly higher rate (13.6%) of C1 cases [Table 5].

Table 5

Comparison between the various studies done for IAC grading system

Studies	C1	C2	C3	C4	C5
Modi et al.[16]	1.36%	72%	3.4%	6.5%	16.7%
Georgieva et al.[21]	25.6%	44.3%	2.2%	5.3%	22.5%
Bajwa and Tariq.[19]	13.6%	60.6%	6.2%	9.3%	10.3%
Sunita et al.[17]	2.9%	50%	3.5%	6.5%	37.1%
Present study	1.3%	82.6%	5.7%	1.7%	8.4%

Our study had 48.3% (90) C2 lesions which included 48% fibroadenoma followed by 32.7% cases of benign breast disease, mastitis (8.6%), fibrocystic disease (6.4%), and galactocele 4% cases. Studies done by Sunita et al.[17] had 50% with fibroadenomas being most common (48.8%) benign lesion followed by fibrocystic disease (13.3%). Similar was the study conducted by Bajwa et al.[19] 67.7% were fibroadenomas followed by fibrocystic disease (16.37%) [Table 5].

The gray zone lesion included C3-13 (5.7%) cases and C4-04 (1.7%) cases. Similar results were also obtained in studies done by Sunita et al.,[17] Al-Kaisi N, et al.,[20] and Georgieva et al.[21] However, the study conducted by Sneige[22] reported 10.4% C3 and 11% C4 cases, while Bajwa et al.[19] had reported 6.2% C3 and 9.3% C4 cases. [Table 5] Our study had 8.4% cases of C5 category which was lower compared to the studies done by Modi et al.[16] 16.7% and Sunita et al.[17] 37.1%.

The presence or absence of nucleoli was found to be a useful feature in cytological grading and correlated well with the histological grade of the tumor. The observations by Black et al.,[23] Moriquand and Pasquier,[24] Hunt et al.,[25] Dabbs[26], and Zoppi et al.[27] agree with the importance of this criteria for grading purpose. All the six cytological grades were strongly and positively correlated with histological grading in the present study. Our observations were in correlation with findings of other workers.[172324252628]

In the present study, cytology grading showed an absolute correlation with the histological grade in 89% (n = 17) cases which was in concordance with studies done by Chandanwale et al.[28] (82.5%) and Pal and Gupta.[29] (78%) and Khan et al.[30] (97.14%). We had two cases which were discordant, one case each from cytologically diagnosed grade I and grade II was finally reported as grade III on histology. The cause of discordance could due to deep seated lesions, pauci-cellularity of smear, subjective variation, and technical error.

Many cytologic grading systems for breast carcinoma are available in the literature with good correlation with Elston–Ellis grading system. Because of more sensitivity, simplicity, more objective set of criteria, and easy reproducibility, Robinson's method is preferred over other methods.[313233]

Cytological categorization based on IAC (international academy of cytology) standardized approach is done. This structured reporting will enhance the reproducibility of reports and creates uniformity in its assessment, especially by clinicians. We conclude that a uniform reporting system for classification and diagnosis of breast lesions is useful as it is directly related to the risk of malignancy in each category. With the comparison between cytohistological nuclear grading, it was concluded that cytoprognostic scores help in evaluating the aggressiveness of tumor and can be used as a prognostic factor for better management of patients and guiding for further neo adjuvant chemotherapy.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.