An audit of histopathology reports of carcinoma endometrium: experience from a tertiary referral center.

BACKGROUND: The aim was to assess compliance to reporting minimum data sets in carcinoma endometrium reports, in a team of 13 pathologists, and also to analyze parameters such as. tumor size, type, grade, depth of myometrial invasion, lymph node yield, pTNM stage etc.
MATERIALS AND METHODS: Reports of 114 cases of carcinoma endometrium, that were operated in-house during the years 2008 to 2010 were analyzed from the files of the Pathology department of our hospital.
RESULTS: The median age was 58.04 years and median tumor size was 4 cm. Endometrioid adenocarcinoma was the most common type (82.5%), followed by malignant mixed Mullerian tumor (MMMT) (6.1%) and Serous carcinoma (3.5%). Grade 2 was the commonest tumor grade (42.1%). Less than half of myometrial invasion was seen in 50% of the cases and more than half of the myometrial invasion was seen in 46.5% of cases. (Information was not available in four cases). Parametrial involvement was seen in 5.3% cases. The pTNM stage was not mentioned in 71.9% reports. The median lymph node yield was 15.
CONCLUSION: The compliance to adhere to and to provide minimum data information in carcinoma endometrium reports is generally good. Lymph node yield is reasonable. Mentioning of pTNM staging is to be done more meticulously. Use of proformas/checklists is recommended.

Introduction

Histopathological reporting of surgically resected cancer specimens requires specific information or confirmation, to determine the extent (stage) of the tumor. This is important to decide the adjuvant therapy and also helps in the quality control of related departments such as radiology and surgery. The minimum datasets needed for reporting have been widely and freely available on websites of reputed international organizations for several years now. The present study was carried out with the objective of assessing compliance to reporting the minimum data sets for carcinoma endometrium histopathology reports as a marker of completeness of the pathology examination and an internal audit of the pathology department.

Materials and Methods

Data retrieval

Files from the Department of Pathology of our hospital (2008-10) were screened. These were seen by a team of 13 pathologists by rotation. Of these, a total of 574 surgical pathology reports were generated that pertained to endometrial pathology. These included ‘in-house’ operated cases, referrals post surgery (slides and/or blocks seen by a pathologist who was outside of the institution) as well as cases that were sent to us for consultation as we are a referral center. We included for the purpose of the study, only cases that were operated in house. Thus, a total of 114/574 cases of carcinoma endometrium were chosen. Exclusions were hysterectomies for fibroids, adenomyoma, and endometriosis.

Procedure followed in department of pathology

The specimens from the operation theatres are sent to our department in fresh state in plastic sealed bags. The specimens are opened and fixed overnight in copious amount of formaline and are then dissected in fixed state as per the standard protocol.[12] Lymph nodes are also dissected after fixation. WHO classification for sub typing the endometrial carcinomas is used.[3] Parametrial connective tissue is blocked in its entirety. We do not practice any fat dissolving solution technique for lymph node harvest. A careful gross examination, palpation, dissection and selection of the bits is done.

Data collection and analysis

Following details were recorded- case number, pathology number, age, nature of surgery, tumor size (including maximum tumor size), tumor type (for example whether endometrioid adenocarcinoma, serous adenocarcinoma or Malignant Mixed Mullerian Tumor), tumor grade, presence and extent of myometrial invasion (less than half or equal to or more than half of myometrial invasion), distance to serosa (whether mentioned or not), lymphatic emboli (seen/not seen), perineural invasion (seen/not seen), isthmic involvement, comment on adjacent endometrium, squamous differentiation, cervical involvement, comment on ovaries and tubes, comment on parametrium, whether frozen section was carried out or not, right and left pelvic lymph nodes (total number; metastatic or not), paraaortic nodes (number and involvement) and any other comments. Descriptive statistics were used with quantitative data being expressed as median and range and qualitative data as percentages.

Results

Demographics- The median age was 58 years (range 34-82) The median tumor size was 4 cm (range 0.4-13 cm) [Table 1].

Table 1

Age and tumor size

Parameter	Mean	Median	Range	SD	Number
Age	58.04	57.5	34-82 yrs	9.985	n=114
Max T size	4.26	4	0.4-13cm	2.223	n=107*

*Maximum tumor size was mentioned in 107 reports

Audit findings: Endometrioid adenocarcinoma was the most common type of carcinoma (n =94; 82.5%), followed by MMMT (n = 7; 6.1%), followed by serous carcinoma n =4; 3.5%) [Table 2]. Grade 2 was the most common tumor grade [Table 3]. Myometrial invasion was less than half in (n =57) 50% of the cases, whereas it was equal to or more than half the thickness in 46.5 % of cases [Table 4]. Distance in millimeters to serosa was mentioned in 54.88% cases. Involvement of the cervix, parametria, lymphatic embolization, perineural invasion, mentioning pTNM stage is given in Table 5. Table 6 shows actual pTNM staging (inferred from the report). Most (111) were laproscopic surgeries, only 3 were open surgeries. ‘Tumorfree distance to serosa’ is the distance of the deepest portion of tumor cells in myometrium to the serosa. This measurement has been identified as an independent prognostic factor in endometrial adenocarcinoma.[12] Comment on the tubes and ovaries were made in all cases. Squamous differentiation in the tumor was mentioned in 17/109 (15.6%) cases. Information about omental tissue, peritoneal tissue biopsy was not uniformly available in all the reports. Out of 15 non-endometrioid type carcinoma reports, omentum was involved by the tumor in 2 cases and negative for tumor in 5 cases. It was not removed in seven cases; in one case peritoneal nodule was removed which was free of tumor. Comment on the vagina was given (free of tumor) in two cases only. In lymph nodes the mean overall lymph node yield was 15.67 with a median of 15 [Table 7]. (Right pelvic nodes: mean=8; median=8; left pelvic nodes: mean=6.97; median=7) (information was not available in 6 cases). In 28 cases (31.92%), paraaortic nodes were removed and frozen section was carried out in 43/114 cases (37.7%).

Table 2

Tumor type

Tumor type	Frequency	Percentage
Endometrioid adenocarcinoma	94	82.5
Serous carcinoma	4	3.5
MMMT	7	6.1
Mixed type carcinoma	3	2.6
Complex hyperplasia	3	2.6
Unremarkable endometrium**	1	0.9
Inflammatory mass	1	0.9
Choriocarcinoma	1	0.9

**Post chemotherapy case

Table 3

Grade of the tumor

		Frequency	Percent	Valid percent	Cumulative percent
Valid	G1	21	18.4	18.4	18.4
	G2	48	42.1	42.1	60.5
	G3	40	35.1	35.1	95.6
	Not known	5	4.4	4.4	100.0
	Total	114	100.0	100.0

G – Grade; Grade of the tumor was not mentioned in 5 cases (4.4%)

Table 4

Depth of myometrial invasion

Parameter	Frequency	Percentage
Less than ½ myometrial invasion	57	50
Up to or more than ½ myometrial invasion	53	46.5

Myometrial invasion was not mentioned in 4 cases (3.5%)

Table 5

Other parameters

Parameter	No involvement (%)	Involvement (%)
Involvement of cervix	86	14
Involvement of parametria	94.7	5.3
LVI	84.2	15.8
PNI	100	0
pTNM stage***	Not given 71.9	Given 24*

***pTNM staging was not applicable in 5 cases; 3 cases — complex atypical hyperplasia, 1 case — inflammatory mass in the endometrium mimicking carcinoma, 1 case — unremarkable endometrium (post chemotherapy case)

Table 6

TNM stage

Stage	Frequency	Percentage
pT1aN0	53	46.5
pT1bN0	33	28.9
pT1aN1	1	0.9
pT1bN1	4	3.5
pT2N0	5	4.4
pT2N1	1	0.9
pT3N0	9	7.9
pT3N1	3	2.6
Not applicable	5	4.4
Total	114	100

Table 7

Lymph node retrieval

Lymph nodes	Mean	Median	Range	SD
Rt. pelvic nodes	8.00	8.00	0-19	4.033
Lt. pelvic nodes	6.97	7.00	0-19	3.611
Total	15.67	15	0-40	7.627

n = 108

Discussion

Minimum data sets (macroscopic and microscopic findings) for all cancers are available.[12] Sections taken at the grossing table depend on the information that is required in the cancer data set. A meticulous report is important as it determines the treatment and prognosis. It also facilitates regular audits and review of all aspects of services. The utility of audits in pathology is well known. Audits can bring out the inadequacies in the histopathology reports.[45] It is well recognized that standardization in cancer reporting improves the completeness and quality of the reports.[678] With respect to similar audits from our country, we came across an audit of rectal carcinoma reports by Nambiar et al. from India.[9]

Comment about the lymphovascular emboli, perineural invasion, involvement of the cervix was mentioned in 100% of the cases. Tumor type was given in all cases. The grade of the tumor was mentioned in 95.5% of the cases. Myometrial invasion was not mentioned in four (3.5%) cases; and tumor size was missing from the reports in seven (6%) cases. Of note is that pTNM stage was not mentioned in 71.9% cases.

The 2009 FIGO staging for endometrial cancer no longer requires the pathologist to distinguish between those carcinomas confined to the endometrium and those showing invasion of the inner half of the myometrium. The tumor is FIGO Stage IA if myometrial invasion is absent or confined to less than the inner half (<50% myoinvasion). The tumor is staged as IB if it involves the outer half of the uterine wall (>50% myoinvasion).

It is a controversial issue as to what is the number of lymph nodes that must be removed for proper staging. Lutman et al. found that pelvic lymph node count ≥12 is an independent prognostic factor for both overall survival (OS) and progressionfree survival (PFS) in patients with FIGO stage I and II with high grade histology.[10] Cragun et al. reported that patients with grade 3 endometrial cancers having more than 11 pelvic nodes removed had improved OS and PFS compared with patients with 11 or fewer nodes removed.[11] Chan et al. showed correlation between increase in the number of lymph nodes removed and number of nodal metastasis. They concluded that the removal of 21 to 25 nodes was considered to significantly increase the probability of detecting at least one lymph node metastasis.[12] Our mean and median lymph node yield is reasonable, but increase in its number is desirable.

Euscher et al found median pelvic LN yield to be 11 and paraaortic LN yield to be 6.[13] After a careful dissection of the lymph nodes from the fat, they submitted the residual fatty tissue in 64% of the cases, to see whether such a practice would result in significant increase in the number of nodes or result in findings that can impact the clinical management. They concluded that standard processing of lymphadenectomy specimens adequately reflects the actual number of lymph nodes obtained in a case of endometrial carcinoma.

In our records, a total of nine cases showed lymph node metastasis (7.9%). This compares to the quoted lymph node positivity in the literature which is 5-11%.[1114] In 28 cases (31.92%), paraaortic nodes were removed. Removal of paraaortic nodes has not been a consistent practice at the start of the 2008 and the practice increased towards 2010; and majority of the paraaortic lymph node removals are from 2010 (6 in 2008, 6 in 2009, and 16 in 2010). The mean paraaortic lymph node yield is 2.71 (median-2, range 0-9).

In summary, the above findings show that compliance with adhering to minimum data information in a team of 13 pathologists is generally good but improvements could be made in several areas. Endometrioid adenocarcinoma is the most common type of endometrial carcinoma. Lymph node yield, in our hands, is reasonable, and constant diligence is required. pTNM staging is one area that needs to be mentioned more meticulously.