Spectrum of histopathological lesions in the fallopian tubes

Correspondence: Dr Adelene Basu, MD Department of Pathology, ESI-PGIMSR, Kolkata, India. E mail: adelene1951@gmail.com Background: Fallopian tubes are common surgical specimen in the pathology laboratory; still there is a lack of data to describe the frequency of various histological fi ndings. The aim and objectives of this study was to describe the various histopathological fi ndings of fallopian tubes.


INTRODUCTION
The fallopian tubes are complex structures that represent more than conduits from ovary to endometrial cavity. 1 It is a common specimen in a pathology laboratory and may be examined either alone as a salpingectomy or tubal ligation specimen, or as part of a more complex specimen from a hysterectomy and/or oophorectomy operation. 2There is a lack of data to describe the frequency of various histological fi ndings in a general surgical pathology practice and only a few attempts have been made to publish the data in the literature.

MATERIALS AND METHODS
The data was collected retrospectively from the department of Pathology, between periods of fi ve years i.e from July 2003 to June 2008.All the specimen of Salpingectomy either done for TAH with BSO, Ligation with / without MTP, unilateral Salpingectomy or Salpingoophorectomy was included in the study.Routinely, at least 2 sections were taken from the fallopian tube if gross pathology is were part of ruptured ectopic pregnancy.Salpingitis was found in 326 fallopian tubes, with maximum cases showing involvement of bilateral tubes.Maximum cases were of chronic nature with only 15 cases of acute salpingitis.Chronic salpingitis included 3 cases of salpingitis isthmica nodosa.Endometriosis (fig.1), tuberculosis, hydrosalpinx and haematosalpinx constituted a small percentage of cases.The diagnosis of endometriosis was established when endometrial glands with endometrial stroma was found embedded within the fallopian tube wall.In all the cases of tuberculosis (fig.2), well formed epithelioid cell granulomas with caseous necrosis were found.Plical adhesions and tubal fibrosis was also noted in these cases.Endometrial tuberculosis was present in all of the cases.Hydrosalpinx and haematosalpinx constituted minority of cases.
Neoplasm of the fallopian tubes was rarely encountered with only 1 case of adenomatoid tumour (fig.3) and 1 case of primary adenocarcinoma of fallopian tube (fig.4).However, metastatic deposits were found in 5 cases, where primary was from gastric adenocarcinoma (1 case), ovarian carcinoma (2 cases), endometrial carcinoma (1 case) and cervical squamous cell carcinoma (1 case).

DISCUSSION
The histologic findings in the fallopian tubes have been described only sporadically in the literature.As this is a common specimen in surgical pathology, knowledge of general frequency of these variations can be valuable to the pathologist who identifies a potentially unusual histologic findings. 2e fallopian tubes were within normal limits in 69.00% of the cases while the rest revealed some tubal pathological lesion.Bagwan et al. 3 found 33.48% of tubes involved by pathological lesions where inflammatory condition (18.05%) of the tube constituted the major group.However, the most common histopathological finding in the present study is ectopic tubal gestation followed by chronic salpingitis.This may be because of the fact that more number of cases has been included in this study, and also, gynecologists evident; otherwise if the fallopian tube is apparently within normal limits, only one section is taken for processing.
Haematoxylin & Eosin stained slides were studied by at least two pathologists in abnormal cases.Paratubal cysts and microscopic examination for tubal metaplasia and embryologic remnants were excluded from the study.

RESULTS
Over a period of 5 years, a total of 28,455 specimens were received in the department of Pathology including fallopian tubes from 2575 patients so accounting for 9.04% of all surgically removed specimens.Total number of fallopian tubes was 4762 from 2575 patients who have undergone various surgical procedures.Fallopian tubes were part of TAH with BSO, unilateral salpingectomy, unilateral salpingo-ophorectomy, tubal ligation without MTP and tubal ligation with MTP in 76.11%, 14.6%, 5.08%, 3.8% and 1.36% cases respectively.(Table1) The maximum number of patients belonged to 36-45 years of age group (46.2%) closely followed by 26-35 years of age group.The youngest patient was a 14 years female where unilateral salpingo-ophorectomy was done for ectopic pregnancy and the eldest was 83 years old who underwent Warthin's Operation for squamous cell carcinoma of cervix.
The fallopian tubes revealed various histopathological findings which were divided into salpingitis, endometriosis, tuberculosis, hydrosalpinx, haematosalpinx and ectopic tubal gestation.Maximum number of fallopian tubes (69.00%) were within normal limits and most of them were part of TAH with BSO specimen.Ectopic tubal gestation constituted 13.5% cases followed by salpingitis in 12.66% cases.(Table 2) Out of 350 cases of ectopic gestation, right tube was involved in 70 cases, left in 62 cases and side along with site was not mentioned in 218 cases.However, in 56 cases which were clinically and radiologically diagnosed as ectopic tubal gestation, histopathological diagnosis of ectopic gestation could not be established due to lack of decidual reaction and absence of trophoblastic cells.In these cases, a diagnosis of chronic non specific salpingitis was given and all the cases enthusiastically send all the specimen of ectopic pregnancy for histopathological examination.

Histopathological lesions in fallopian tubes
Ectopic pregnancy is a dangerous and potentially lifethreatening condition and as many as 95% of all ectopic pregnancies occur within the fallopian tubes. 4Hunt et al. 2 found ectopic decidua in 3% specimens of postpartum patients present in both subserosal and plical areas.Decidual reaction in both these sites along with presence of chorionic villi was seen in this study also in 350 out of 406 cases while in rest of the 56 cases, diagnosis of ectopic gestation could not be established due to lack of decidual reaction and absence of trophoblastic cells.Kirichenko et al. 5 analyzed fallopian pregnancy morphologically and immunohistochemically, and found that decidual reaction was not developed in majority of cases which could be the reason of limitless invasion of cytotrophoblast and hemosalpinx development which is in accordance with the present study.
Salpingitis is inflammation of the fallopian tubes, most commonly caused by sexually transmitted micro-organisms in adolescent and adult women.It is rarely found in sexually inactive girls and generally the result of a blood-borne or genitourinary infection. 6Infertility and an increased chance of ectopic pregnancy are the most important long term complications of salpingitis.The rate of infertility is approximately 15% after a first episode of salpingitis and increases to 50% after a third episode. 7,8We found evidence of chronic non specific salpingitis in 56 cases of clinically diagnosed ruptured ectopic tubal gestation where diagnosis could not be established histopathologically.
Endometriosis is defined as the presence of ectopic endometrial tissue outside the lining of the uterine cavity and is fairly common in childbearing women.Endometriosis frequently involves the tubes in the form of nodules located in the wall or serosa. 9Microscopically, foci of endometriosis was found located within the wall of the tubes in maximum number of cases in this study.
Tuberculosis of the fallopian tube develops commonly by hematogenous spread of the organism, usually from a primary pulmonary infection and rarely by direct extension from adjacent organs or lymphatic spread from intestinal tuberculosis.Agarwal et al10 did a clinic-pathologic study of female genital tuberculosis and found the incidence declining from 1.8% in 1974 to 0.8% in 1989 and onwards.They noted the involvement of endometrium in 99.5%, fallopian tubes in 94.7%, cervix in 81.5%, ovaries in 62.5% and vagina in 0.2% cases.All cases (100%) of fallopian tube tuberculosis had concomitant involvement of endometrium in our study.It may be attributed to the declining incidence of genital tract tuberculosis, late presentation of the patient or less number of tubercular salpingitis patients studied in the present study.
Primary tubal neoplasms are rare and are usually only recognised at surgery or on pathological examination of the excised specimen. 3Primary fallopian tube adenocarcinoma accounts for 1% of all female genital tract malignancies. 11nly one case of primary adenocarcinoma was seen in this study accounting for 0.03% of all the specimens.Majority of the patients with primary adenocarcinoma of fallopian tube present with stage 1 disease at diagnosis but their survival probability is low compared with other early stage gynecological malignancies. 12Longacre et al. 13 attributed low incidence of primary malignancy in part due to admittedly arbitrary definitional criteria as it is difficult to distinguish primary tubal carcinoma from primary ovarian or primary endometrial carcinoma in patients with high stage disease.It is essential for the pathologist to section the fallopian tubes serially and submit all of the tissue for microscopic examination so that the diagnosis of carcinoma is not missed. 14 comparison, metastatic tumours were more commonly encountered (5 cases) in the specimen with primary from ovarian (2 cases), endometrial (1 case), gastric adenocarcinoma (1 case) and squamous cell carcinoma cervix (1 case).Hunt et al. 2 noted metastatic carcinoma in 1.4% of fallopian tubes with tumour cell deposits as serosal implants, intraluminal tumour or infiltrating the plicae and muscularis propria.Most of the examples represent spread of an ovarian or endometrial adenoarcinoma along the peritoneal surface or through the lumen.Metastases to the tube usually come from ovarian adenocarcinoma followed by endometrial or cervical adenocarcinoma. 15Tubal metastases usually indicate poor prognosis regardless of the site of primary tumour. 16 contrast to malignant tumours, benign tumours of the fallopian tubes are rare, most frequent of which is adenomatoid tumour.It is usually an incidental finding as also in present study.Its main interest to gynecologist lies in the fact that it can be mistaken for malignancy if the clinician is not aware and histopathology is the main stay to confirm the diagnosis.

CONCLUSION
Though the fallopian tubes remain unremarkable in majority of the surgical pathological specimens, it must be subjected for histopathological examination to demonstrate the pathological lesions and also, it is essential for the pathologist to section the fallopian tubes serially and submit all of the representative tissue for microscopic examination so that the diagnosis of these pathological entities is not missed.

Table 1 : Distribution of cases according to the type of surgery performed
TAH-BSO:Total abdominal hysterectomy with bilateral salpingoophorectomy, ULSO: Unilateral salpingoophorectomy, ULS: Unilateral salpingoophorectomy