ORIGINAL ARTICLE
Histologic confirmation of endometriosis in different peritoneal lesions MEITE H. MOEN'AND TOREB. HALVORSEN' From the 'Department of Obstetrics and Gynecology and the 2Department of Pathology, University Hospital of Trondheim, Trondheim, Norway
Acta Obstet Gynecol Scand 1992; 71: 337-342
The aim of this study was to compare the macroscopic evaluation of peritoneal abnormalities suspected of endometriosis with the histologic examination of the tissue. Peritoneal biopsies from 152 patients investigated for gynecological problems (94) or undergoing tuba1 sterilization (58) were taken from macroscopically abnormal peritoneum, and examined for the presence of endometriosis. Endometriosis was histologically confirmed by the presence of both endometrioid glands and stroma. Endometriosis was confirmed in 78 of the patients (51%). If the diagnostic criteria were extended also to include endometrioid stroma lacking glands, but containing iron pigment and/or hemorrhage, 82 patients (54%) were positive for endometriosis. Endometriosis was histologically confirmed in 76% of pigmented lesions, in 57% of clear or red papules, in 12% of peritoneal pockets, and in 16% when only fibrosis or scarring was observed. Half of the samples with confirmed endometriosis exhibited cyclic activity. The reproducibility of the histologic evaluation was satisfactory. A high rate of negative biopsies emphasizes the need of taking biopsies from peritoneal lesions suspected of endometriosis for confirmation of the diagnosis. Key words: endometriosis; peritoneal lesions; histologic criteria Submitted October 30, 1991 Accepted January 29, 1992
Endometriosis is one of the most common gynecological disorders of women in their reproductive years, in some cases causing pelvic pain and/or infertility, but it is also found occasionally in women without symptoms. Often the diagnosis of endometriotic implants on the peritoneum has been established simply by direct visualization through the laparoscope. In recent years, there has been rising awareness of subtle manifestations of endometriosis such as non-pigmented lesions (1) and endometriosis hidden in peritoneal defects ( 2 ) , thus histologic confirmation of biopsies has become more important. The diagnosis of endometriosis depends initially on the gynecologist's knowledge of different macroscopic types of endometriotic lesions and a careful biopsy-taking, and secondly on the histologic examination made by the pathologist.
The aim of the present investigation was to study the rate of agreement between the different macroscopic manifestations of endometriosis and the histologic confirmation, and secondly to evaluate the reproducibility of the histologic evaluation of peritoneal biopsies.
Material and methods From 1986 to 1990 the gynecologist (MHM) consecutively registered peritoneal biopsies from 153 patients investigated for infertility (24) or pelvic pain (64), or sterilized either as an interval procedure (33) or in connection with a first trimester abruption of pregnancy (25), or investigated for other reasons (7) such as suspected ectopic pregnancy. The age of Acta Obstet Gynecol Scand 71 (1992)
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M . H. Moen and T. B. Halvorsen
Fig. I . Classic blue-black endometriotic lesions. (With permission from Martin D C (ed): Laparoscopic Appearance of Endomerriosis. Memphis: Resurge Press, 1991.)
Fig. 2. Clear glandlike lesions (papules). (With permission from Martin D C (ed): Laparoscopic Appearance of Endomerriosis. Memphis: Resurge Press, 1991.)
the patients (mean f SD) was 33.2 f 7.3 years (range 18 to 49 years). The phase of the menstrual cyclus was calculated from the beginning of the last period, but information was missing from 23 of the patients. The patients were examined by laparoscopy in 148 cases. by laparotomy in five cases. In 49% of cases the operations were undertaken by the first author
(MHM), in 35% of cases by members of the fertility
Fig. 3. Red glandlike lesions (papules). (With permission from Martin D C (ed): Laparoscopic Appearance of Endornetriosis. Memphis: Resurge Press, 1991.)
research unit and in 16% o f cases by the rest of the gynecological staff. A description of the macroscopic appearance and location was given. In cases with typical manifestations of endometriosis, sketches were made on the American Fertility Society's revised classification scheme (3). Biopsies were taken with a sharp forceps from peritoneum suspected of endometriosis such as black or blue lesions (Fig. 1). yellow-brown patches and clear (Fig. 2) or red Fig. 4. Peritoneal defect (pockct).
Diagnosing endometriosis Table I. Endometrioid stroma and glands demonstrated in peritoneal biopsies from 152 patients. Number of patients (percentages)
Glands present Glands absent
Stroma present
Stroma absent
78 (51%) 9 YO)^
10 (7%)” 55 (36%)
Hemorrhagic areas and/or iron pigment deposits present in three cases and four cases respectively.
(Fig. 3) glandlike structuresipapules, or from peritoneum which could harbor endometriosis such as peritoneal defectdpockets (Fig. 4), adhesions and scarring. Usually more than one biopsy was taken from each patient (mean 2.3 biopsies, range 1-6 per patient). The total amount of tissue obtained per patient had an average diameter of 7.7 mm (range 2-22 mm). The biopsies were immediately fixed in 4% neutral aqueous formaldehyde and transferred to the department of pathology. The biopsies were embedded in paraffin as one block from each patient and sectioned at 5 micron thickness. Pairs of sections from the same block were stained with hematoxylin-eosin-saffron (HES), and with Turnbull’s stain for iron pigment. The slides were all examined by one pathologist (TBH) who had no knowledge of the clinical details. The presence of endometrioid glands, endometrioid (cytogenic) stroma, decidua-like stromal reaction, hemorrhagic areas, iron pigment, granulation tissue, areas with fibrosis, and calcified areas was noted. Fibrosis was defined as increased amount of subperitoneal collagenous fibres relative to that of normal peritoneum. When both endometrioid glands and stroma were found, the lesions were classified as proliferative if mitoses were observed in glands and/or stromal cells, as secretory if definite secretory signs were observed, otherwise they were classified as non-cyclic. Only lesions exhibiting both endometrioid glands and stroma were classified as definite endometriosis. After an interval of four weeks, the slides were renumbered randomly and re-exam-
339
ined to test the reproducibility of the histologic evaluations. The final histologic results were obtained by random drawing from the results of the first and second examination.
Statistical methods The proportion of agreement achieved beyond that attributable to chance was expressed by the Kappa coefficient (4). Standard error of the Kappa was estimated using an abbreviated formula suggested by Silcocks (5). Kappa coefficients were calculated for intra-observer evaluation of histologic samples. An estimate of Kappa less than 0.4 represents poor agreement, Kappa between 0.4 and 0.75 is taken for moderate agreement, and Kappa above 0.75 represents good agreement (6). In addition, chi-square test (with Yates correction when appropriate) was used, and a p-value of less than 0.05 was considered as statistically significant.
Results The peritoneal lesions seen during the operation could be classified in seven categories: blue or black pigmented foci (57 cases), yellow-brown patches (9 cases), clear papules (31 cases), red papules (24 cases), peritoneal pockets (41 cases), adhesions (22 cases) and scarring (38 cases). More than one feature was found in some of the cases, so 222 lesions were described in 153 patients. In 93 patients, only one type of peritoneal abnormality was observed. Biopsy from one of the 153 patients contained insufficient material for histologic evaluation, so 152 samples remained for the study. Definite endometriosis (Table I) was observed in 78 of 152 (51%) of the cases by the presence of both glands and stroma. In 10 cases glands were, present but stroma absent, in nine cases stroma was present but glands absent. As the biopsies taken from different lesions
Table 11. Histologic examination of peritoneal biopsies from different macroscopic lesions where only one type of abnormality was seen in each patient (n = 93)
Pigmented foci: blue or black spots or yellow-brown patchcs Clear or red papules Peritoneal pockets Adhesions or scarring
Number of patients
Endometriosis verified in number of patients (percentage)
25 23 26 19
19 (76%) 13 (57%) 3 (12%) 3 (16%) Acta Obster G‘ynecol Scand 71 (1992)
340
M.H. Moen and T. B. Halvorsen
Table 111. Histologic features present in first and second examination of 152 peritoneal biopsies with Kappa coefficient ( 2 2 SE) of the reproducibility. Final results are obtained from random drawing between the first and second examination First examination ( n = 152)
Second examination ( n = 152)
Kappa coefficient (+2 SE)
Final result ( n = 152)
Endometrioid glands Endometrioid stroma Decidua-like stromal reaction Hcmorrhagic areas Iron pigment deposits Fibrosis Granulation tissue Calcified areas
87 91 18 32 69 97 4 1s
87 86 23 27 78 126 4 17
0.95t0.04 0.85+0.08 0.80k0.14 0.64k0.16 0.86k0.08 0.37k0.14 0.23f0.60 0.72+0.20
88 87 20 29 74 115 4 17
Endometriosis verified
81
77
0.92 k0.06
78
Histologic features present in number of patients:
in the same patient were moulded in one block, the relation between the macroscopical picture and the histologically proved endometriosis could only be evaluated from patients where just one type of lesion was demonstrated. This was the situation in 93 cases, and the results of the corresponding biopsies are seen in Table 11. The confirmation rate for definite endometriosis was highest for pigmented lesions (76%) and clear and red papules (57%), lowest for adhesions or fibrosis (16%) and peritoneal defects (12%). In the total material, pigmented lesions were significantly more often present in cases where endometriosis was histologically verified than in nonverified (60% versus 22%, p
Histologic confirmation of endometriosis in different peritoneal lesions MEITE H. MOEN'AND TOREB. HALVORSEN' From the 'Department of Obstetrics and Gynecology and the 2Department of Pathology, University Hospital of Trondheim, Trondheim, Norway
Acta Obstet Gynecol Scand 1992; 71: 337-342
The aim of this study was to compare the macroscopic evaluation of peritoneal abnormalities suspected of endometriosis with the histologic examination of the tissue. Peritoneal biopsies from 152 patients investigated for gynecological problems (94) or undergoing tuba1 sterilization (58) were taken from macroscopically abnormal peritoneum, and examined for the presence of endometriosis. Endometriosis was histologically confirmed by the presence of both endometrioid glands and stroma. Endometriosis was confirmed in 78 of the patients (51%). If the diagnostic criteria were extended also to include endometrioid stroma lacking glands, but containing iron pigment and/or hemorrhage, 82 patients (54%) were positive for endometriosis. Endometriosis was histologically confirmed in 76% of pigmented lesions, in 57% of clear or red papules, in 12% of peritoneal pockets, and in 16% when only fibrosis or scarring was observed. Half of the samples with confirmed endometriosis exhibited cyclic activity. The reproducibility of the histologic evaluation was satisfactory. A high rate of negative biopsies emphasizes the need of taking biopsies from peritoneal lesions suspected of endometriosis for confirmation of the diagnosis. Key words: endometriosis; peritoneal lesions; histologic criteria Submitted October 30, 1991 Accepted January 29, 1992
Endometriosis is one of the most common gynecological disorders of women in their reproductive years, in some cases causing pelvic pain and/or infertility, but it is also found occasionally in women without symptoms. Often the diagnosis of endometriotic implants on the peritoneum has been established simply by direct visualization through the laparoscope. In recent years, there has been rising awareness of subtle manifestations of endometriosis such as non-pigmented lesions (1) and endometriosis hidden in peritoneal defects ( 2 ) , thus histologic confirmation of biopsies has become more important. The diagnosis of endometriosis depends initially on the gynecologist's knowledge of different macroscopic types of endometriotic lesions and a careful biopsy-taking, and secondly on the histologic examination made by the pathologist.
The aim of the present investigation was to study the rate of agreement between the different macroscopic manifestations of endometriosis and the histologic confirmation, and secondly to evaluate the reproducibility of the histologic evaluation of peritoneal biopsies.
Material and methods From 1986 to 1990 the gynecologist (MHM) consecutively registered peritoneal biopsies from 153 patients investigated for infertility (24) or pelvic pain (64), or sterilized either as an interval procedure (33) or in connection with a first trimester abruption of pregnancy (25), or investigated for other reasons (7) such as suspected ectopic pregnancy. The age of Acta Obstet Gynecol Scand 71 (1992)
338
M . H. Moen and T. B. Halvorsen
Fig. I . Classic blue-black endometriotic lesions. (With permission from Martin D C (ed): Laparoscopic Appearance of Endomerriosis. Memphis: Resurge Press, 1991.)
Fig. 2. Clear glandlike lesions (papules). (With permission from Martin D C (ed): Laparoscopic Appearance of Endomerriosis. Memphis: Resurge Press, 1991.)
the patients (mean f SD) was 33.2 f 7.3 years (range 18 to 49 years). The phase of the menstrual cyclus was calculated from the beginning of the last period, but information was missing from 23 of the patients. The patients were examined by laparoscopy in 148 cases. by laparotomy in five cases. In 49% of cases the operations were undertaken by the first author
(MHM), in 35% of cases by members of the fertility
Fig. 3. Red glandlike lesions (papules). (With permission from Martin D C (ed): Laparoscopic Appearance of Endornetriosis. Memphis: Resurge Press, 1991.)
research unit and in 16% o f cases by the rest of the gynecological staff. A description of the macroscopic appearance and location was given. In cases with typical manifestations of endometriosis, sketches were made on the American Fertility Society's revised classification scheme (3). Biopsies were taken with a sharp forceps from peritoneum suspected of endometriosis such as black or blue lesions (Fig. 1). yellow-brown patches and clear (Fig. 2) or red Fig. 4. Peritoneal defect (pockct).
Diagnosing endometriosis Table I. Endometrioid stroma and glands demonstrated in peritoneal biopsies from 152 patients. Number of patients (percentages)
Glands present Glands absent
Stroma present
Stroma absent
78 (51%) 9 YO)^
10 (7%)” 55 (36%)
Hemorrhagic areas and/or iron pigment deposits present in three cases and four cases respectively.
(Fig. 3) glandlike structuresipapules, or from peritoneum which could harbor endometriosis such as peritoneal defectdpockets (Fig. 4), adhesions and scarring. Usually more than one biopsy was taken from each patient (mean 2.3 biopsies, range 1-6 per patient). The total amount of tissue obtained per patient had an average diameter of 7.7 mm (range 2-22 mm). The biopsies were immediately fixed in 4% neutral aqueous formaldehyde and transferred to the department of pathology. The biopsies were embedded in paraffin as one block from each patient and sectioned at 5 micron thickness. Pairs of sections from the same block were stained with hematoxylin-eosin-saffron (HES), and with Turnbull’s stain for iron pigment. The slides were all examined by one pathologist (TBH) who had no knowledge of the clinical details. The presence of endometrioid glands, endometrioid (cytogenic) stroma, decidua-like stromal reaction, hemorrhagic areas, iron pigment, granulation tissue, areas with fibrosis, and calcified areas was noted. Fibrosis was defined as increased amount of subperitoneal collagenous fibres relative to that of normal peritoneum. When both endometrioid glands and stroma were found, the lesions were classified as proliferative if mitoses were observed in glands and/or stromal cells, as secretory if definite secretory signs were observed, otherwise they were classified as non-cyclic. Only lesions exhibiting both endometrioid glands and stroma were classified as definite endometriosis. After an interval of four weeks, the slides were renumbered randomly and re-exam-
339
ined to test the reproducibility of the histologic evaluations. The final histologic results were obtained by random drawing from the results of the first and second examination.
Statistical methods The proportion of agreement achieved beyond that attributable to chance was expressed by the Kappa coefficient (4). Standard error of the Kappa was estimated using an abbreviated formula suggested by Silcocks (5). Kappa coefficients were calculated for intra-observer evaluation of histologic samples. An estimate of Kappa less than 0.4 represents poor agreement, Kappa between 0.4 and 0.75 is taken for moderate agreement, and Kappa above 0.75 represents good agreement (6). In addition, chi-square test (with Yates correction when appropriate) was used, and a p-value of less than 0.05 was considered as statistically significant.
Results The peritoneal lesions seen during the operation could be classified in seven categories: blue or black pigmented foci (57 cases), yellow-brown patches (9 cases), clear papules (31 cases), red papules (24 cases), peritoneal pockets (41 cases), adhesions (22 cases) and scarring (38 cases). More than one feature was found in some of the cases, so 222 lesions were described in 153 patients. In 93 patients, only one type of peritoneal abnormality was observed. Biopsy from one of the 153 patients contained insufficient material for histologic evaluation, so 152 samples remained for the study. Definite endometriosis (Table I) was observed in 78 of 152 (51%) of the cases by the presence of both glands and stroma. In 10 cases glands were, present but stroma absent, in nine cases stroma was present but glands absent. As the biopsies taken from different lesions
Table 11. Histologic examination of peritoneal biopsies from different macroscopic lesions where only one type of abnormality was seen in each patient (n = 93)
Pigmented foci: blue or black spots or yellow-brown patchcs Clear or red papules Peritoneal pockets Adhesions or scarring
Number of patients
Endometriosis verified in number of patients (percentage)
25 23 26 19
19 (76%) 13 (57%) 3 (12%) 3 (16%) Acta Obster G‘ynecol Scand 71 (1992)
340
M.H. Moen and T. B. Halvorsen
Table 111. Histologic features present in first and second examination of 152 peritoneal biopsies with Kappa coefficient ( 2 2 SE) of the reproducibility. Final results are obtained from random drawing between the first and second examination First examination ( n = 152)
Second examination ( n = 152)
Kappa coefficient (+2 SE)
Final result ( n = 152)
Endometrioid glands Endometrioid stroma Decidua-like stromal reaction Hcmorrhagic areas Iron pigment deposits Fibrosis Granulation tissue Calcified areas
87 91 18 32 69 97 4 1s
87 86 23 27 78 126 4 17
0.95t0.04 0.85+0.08 0.80k0.14 0.64k0.16 0.86k0.08 0.37k0.14 0.23f0.60 0.72+0.20
88 87 20 29 74 115 4 17
Endometriosis verified
81
77
0.92 k0.06
78
Histologic features present in number of patients:
in the same patient were moulded in one block, the relation between the macroscopical picture and the histologically proved endometriosis could only be evaluated from patients where just one type of lesion was demonstrated. This was the situation in 93 cases, and the results of the corresponding biopsies are seen in Table 11. The confirmation rate for definite endometriosis was highest for pigmented lesions (76%) and clear and red papules (57%), lowest for adhesions or fibrosis (16%) and peritoneal defects (12%). In the total material, pigmented lesions were significantly more often present in cases where endometriosis was histologically verified than in nonverified (60% versus 22%, p
