Female Reproductive System Pathology PDF

PATHOLOGY OF THE FEMALE REPRODUCTIVE SYSTEM Annas Salleh Department of Veterinary Laboratory Diagnosis Faculty of Veterinary Medicine Universiti Putra Malaysia 43400 Serdang, Selangor MALAYSIA ...

PATHOLOGY OF THE FEMALE REPRODUCTIVE SYSTEM Annas Salleh Department of Veterinary Laboratory Diagnosis Faculty of Veterinary Medicine Universiti Putra Malaysia 43400 Serdang, Selangor MALAYSIA  Content The entire pathology of the female reproductive system class consist of the following: 1. Theoretical lecture: Pathology of the female reproductive system 2. Case studies: 1. Metastatic mammary tumor in a female hybrid tiger 2. Female reproductive lesions in Malaysia’s last Sumatran Rhinoceros 3. Pregnancy toxaemia in doe 4. Unusual uterine tumor in a bitch 3. Diagnostic guide: Canine mammary gland tumors  General considerations The main functions of the female reproductive tract is to fertilize (egg), implant (zygote), maintain (fetus) and deliver (offspring) The system consists of several organs that fulfill these functions: Ovary, fallopian tube, uterus, cervix, vagina  General considerations Ovary produce eggs from germinal follicle in response to the hormones produced by the pituitary gland itself is an endocrine organ that produces estrogen by the Graafian follicle and progesterone by the corpus luteum Fallopian tube (oviduct) where fertilization occurs successful transportation of the fertilized egg to be implanted in the horn of uterus  General considerations Uterus where the zygotes are implanted, either right or left horn of uterus provides a suitable environment for foetal development by: – controlling the body reaction on foetus via Progesterone – providing nutrient for foetal development via placentome uterine wall produces prostaglandin to lyse the corpus luteum and re-start follicular development  General considerations Cervix function in: – allowing spermatozoa to enter and travel to the fallopian tube during oestrus for fertilization (cervix open) – isolating the uterus from the ‘outside world’ during pregnancy (cervix closed) Vagina where spermatozoa are deposited following natural breeding is not sterile; contains many normal flora  Hormonal functions Major Hormonal Influence of Female Reproduction: Pregnancy Hypothalamus/Pituitary gland Fertilization NonF 1. FSH 3. Luteinizing hormone Ovulation 2. Estrogenic surge [negative feedback] Ovary Inactive Ovary [Follicular Development] Silent Estrus Failure of Ovulation Cystic Ovary Failure in Fertility  Pathology of the Ovary Ovarian Cysts Presence of cyst(s) of >1cm in diameter in the ovary the most common cause of livestock infertility; 85% of the culled, – infertile cows had ovarian cysts there are several types of ovarian cysts, but the three (3) types most commonly – encountered in cows: Cystic Graafian follicle (follicular cyst) Luteinized cyst (luteal cyst) Cystic corpus luteum  Pathology of the Ovary Cystic Graafian follicle (follicular cyst) the most common type of ovarian cyst; more in high-producing cows arises from the failure of Graafian follicle to rupture due to the failure of the release of pituitary gonadotrophin at the early estrus mature follicles are not exposed to the ovulating and luteinizing action of luteinizing hormone resulted in one or more large follicles of >2cm in diameter present in one or both ovaries the cysts appear similar to the mature Graafian follicle but: the cysts have thicker wall the vulva is oedematous, the cervix is enlarged with grey-white mucus the uterus is oedematous and flabby Histologically, the ovum is absent Associated with anestrus, nymphomania, irregular oestrus cycle, infertility  Pathology of the Ovary Luteinized cyst (luteal cyst) develops when there is delayed or insufficient release of luteinizing hormone during estrus same pathogenesis, but follicular cyst no luteinizing hormone while luteinized cyst delayed or insufficient luteinizing hormone usually single cyst with evidence of luteinization and ovulation the cavity of the cysts appears spherical and lined by a layer of fibrous tissue Associated with anestrus, delayed estrus and ovulation, and infertility  Pathology of the Ovary Cystic corpus luteum occurs following ovulation but with formation of cystic cavity in the centre of the developing corpus luteum the cyst is not larger than 5mm diameter, detectable 4-8 days after ovulation the pathogenesis is unknown and the affected corpus luteum can function normally Generally does not affect the reproductive performance, but misdiagnosis may happen.  Ovarian Neoplasia Ovarian neoplasms are uncommonly encountered in veterinary medicine. Occasionally, they are incidentally encountered during ovariohysterectomy. Will not be covered.  Pathology of the Fallopian Tube Fallopian tube Small tubal structure with tiny lumen, lined by ciliated epithelium Where fertilization occurs Function is to provide assistance for egg and sperm toward fertilization Failure of this function leads to ‘repeat breeding’ in females since – the animal is cycling normally due to normal functioning ovaries Normal oviduct  Pathology of the Fallopian Tube Salpingitis Inflammation of the Fallopian tube (oviduct) Usually accompanies other female reproductive lesions (eg. Pyometra, endometritis) Usually bilateral and undetected macroscopically Either serous, catarrhal or fibrinous inflammation  Pathology of the Fallopian Tube Salpingitis (cont.) In the mildest form, the mucosa alone is affected with congested mucosal vessels, few mononuclear infiltration, loss of epithelial cilia and few desquamated cells. More severe infection, catarrhal exudate may be detected in the lumen, thickened mucosa due cell infiltration and parts of the epithelial layer is destroyed Chronic salpingitis shows the mucosa which is destroyed, thickened plica, and replaced by proliferated connective tissue and cellular infiltration. The lumen is smaller, and occluded by cellular debris and thickened plica. Chronic salpingitis  Pathology of the Fallopian Tube Salpingitis (cont.) Salpingitis leads to infertility (repeat breeding) due to the following mechanisms: – Loss of cilia slows down the movement of spermatozoa – Stenosis of the lumen prevents smooth travel of the spermatozoa and/or ovum to fertilization Destructed epithelium unable to: – Facilitate propulsion of the ovum – Facilitate dissolution of cumulus oophorus prior to fertilization – Maintain luminal environment for survival of the ovum and spermatozoa  Pathology of the Fallopian Tube Hydrosalpinx Distension of the Fallopian tube due to the accumulation of fluid – Usually as a result of loss of patency (blocked) lumen Blocked lumen is usually a consequence of inflammatory reaction of surrounding tissues, usually the wall of Fallopian tube and occasionally the wall of uterine horn The most common inflammation that results in hydrosalpinx is traumatic following manual manipulation of the ovary Occasionally, chronic infective inflammation in the tube or uterus leads to stenosis of the lumen that resulted in hydrosalpinx  Pathology of the Fallopian Tube Hydrosalpinx (cont.) Lesions (traumatic): – Distended Fallopian tube with clear watery mucus: – Adhesion of Fallopian tube to ovary – Some haemorrhages and blood clots Lesion (infective): – Chronic inflammation with stenosis, particularly near the tip of uterine horn  Pathology of the Fallopian Tube Pyosalpinx Distension of the Fallopian tube due to the accumulation of pus as a result of pyogenic bacteria infection Consequence of acute inflammatory reaction of surrounding tissues, usually in the wall of Fallopian tube or ascending infection from uterus The blocked or lumen stenosis accumulates pus leading to pyosalpinx Lesions: – Distended Fallopian tube with pus – Acute inflammation; entire thickness of the wall of the tube is infiltrated with neutrophils, lymphocytes, plasma cells and some cellular debris – Occasionally, localised peritonitis  Pathology of the Uterus General Considerations The normal non-pregnant uterus is under the estrogen influence, and highly resistant to infection including the important reproductive diseases such as brucellosis, campylobacteriosis and trichomoniasis The resistance is brought through the production of antibodies and the presence of normal uterine leukocytes Uterus under the influence of progesterone, which includes pregnant uterus, is very susceptible to many non-specific bacteria Therefore, critical times for uterine infection are post-coital and post- Normal uterus parturient  Pathology of the Uterus INFLAMMATION Endometritis Inflammation of the endometrium or uterine mucosa Usually caused by less pathogenic organisms such as Trichomonas foetus, Campylobacter fetus, pyogenic cocci and coliforms Post-coital infection produces no gross lesions but histology reveals: – Mild infiltration of inflammatory cells, particularly neutrophils – Usually there is infiltration of plasma cells with Normal uterus histology occasional foci of lymphocytes – Desquamation of superficial epithelium Although endometritis is mild, it may lead to infertility or abortion  Pathology of the Uterus INFLAMMATION Endometritis (cont.) Puerperal infection (post-parturient) leads to more severe grade of endometritis – Grossly: Uterus is enlarged and flabby lumen contains chocolate-coloured lochia mixed with greyish-yellow content of cellular debris – Histology: haemorrhages congested mucosa infiltration of leukocytes in the mucosa and endometrial glands Endometritis abnormal endometrial gland bacterial colonies may be noted  Pathology of the Uterus Endometritis (cont.) Chronic Endometritis: prolonged presence of inflammation of the endometrium The lesions consist of the followings: – Fibrosis – Leukocytosis with prominent presence of plasma cells – Thickened endometrium by inflammation – Depleted glands. Those present are atrophied, flattened or cystic – Mucosal lining either intact, denuded in places of showing foci of polypoid hyperplasia or squamous metaplasia – Caruncles may be replaced by scar tissues Chronic endometritis  Pathology of the Uterus Metritis Inflammation of all layers of the uterine wall, usually with vaginal discharge Affected uterine wall is thickened with congested blood vessels and oedema fluid and is very friable Serosal surface is dull with petechial or paint-brush haemorrhages The exudate/discharge is foetid and dirty yellow or red-black in colour Occasionally, there is perforation that leads to secondary peritonitis and death due to toxaemia Histological feature reveal purulent inflammation – Mucosal layer is infiltrated with neutrophils – Haemorrhagic – Necrotic, and desquamated cells – Subserosal layer is oedematous and infiltrated with neutrophils – Myometrial blood vessels show similar inflammatory lesions  Pathology of the Uterus Sequele of Endometritis and Metritis Many cases of endometritis, which are mild, spontaneously recover to health and fertility Some cases of metritis, particularly the severe cases, lead to deaths Other cases leads to: – Chronic endometritis – Uterine abscessation – Parametritis – Salpingitis – Pyometra REPRODUCTIVE FAILURE; INFERTILITY  Pathology of the Uterus Pyometra accumulation of pus within the lumen of uterus with open or closed cervix A result of complicated sequale of uterine infection by pyogenic bacteria The essential component of pyometra is the presence of corpus luteum, which is retained beyond its normal cyclic span  Pathology of the Uterus Pathogenesis: Ovulation Persisted Corpus Luteum Degenerates Prostaglandin Progesterone by uterus No Prostaglandin No Fertilization No Pregnancy Endometrial infection (post-coital/post-partum) Pyometra Destruction of Endometrium  Pathology of the Uterus Positional Changes Torsion Uterine torsion is twisted uteri observed mainly in cows following pregnancy, pyometra or hydrometra Minor degrees of torsion, up to 90o are quite frequent in cows but apparently resolve themselves Twisted in excess of 180o is of importance since it may results in: Local circulatory disturbances leading to: Congested and oedematous uterus Oedematous placenta Foetal death Necrotic and friable uterine wall leading to uterine rupture *Correction using Schaffer’s method.  Pathology of the Uterus Prolapse A condition when all or parts of the uterus came out through the vulva and exposed to the outside environment Observed mainly in cows, involving previously gravid uterus Predisposing factors include: – Prolonged dystocia relieved by forced traction – Retained placenta – Hyper-estrogenism leading to prolapse after parturition Affected uterus shows congestion, oedema, followed by haemorrhages, necrosis and sepsis. Gangrene can follow.  Pathology of the Uterus Rupture Uterine rupture can occur spontaneously but usually following obstetrical manipulations Most uterine ruptures occur in the fundus, adjacent to the pelvic brim Usually involves uterus which are devitalized due to torsion or prolonged dystocia but can involve only the mucosal or full uterine wall Mucosal ruptures have less consequences but complete ruptures are often fatal due to severe haemorrhages, peritonitis or shock  Pathology of the Uterus Disturbance in Endometrial Growth Cystic Endometrial Hyperplasia Sometime it is called cystic hyperplastic endometritis Most common in dogs and cats; occasionally in mares and cows Developed following excessive and prolonged estrogenic stimulation of the uterus In ruminants: – exogenous: consumption of estrogenic plants – endogenous: production of estrogens by sex cord stromal tumors of the ovary In queen and bitch: – Exogenous: iatrogenic administration of estrogen – Endogenous: heightened sensitivity of the endometrium to stimulation by endogenous progesterone Infertility is the main consequences of cystic endometrial hyperplasia The affected uterine wall is soft, thick and spongy The mucosa lining appears glistening, moist with numerous submucosal cysts (1-5cm in diameter in horses; 2mm in dogs and cats) bulging like blisters Histology: many cysts of various sizes, lined by cuboidal to attenuated epithelial cells, supporting stroma is fibrotic or oedematous  In Utero Foetal Death Abortion and Stillbirth abortion is a condition when non-full term dead foetus stillbirth is a condition when full-term dead foetus is expelled from the uterus is expelled from the uterus Abortion is a sequel of intrauterine foetal death due to Stillbirth is usually associated with malnutrition of specific infection, toxin, nutritional or physical trauma pregnant mothers or mild infection during late Brucellosis, listeriosis and toxoplasmosis are among the pregnancy involving few placentome important infections that lead to abortion These lead to development of small and weak foetus Infections cause necrosis of the placentome leading to that died during parturition or soon after inhibition of the blood and nutritional supplies to the developing foetus  In Utero Foetal Death Foetal mummification presence of dead, dried and mummified foetus in the uterus Prerequisite: no infection The fluid of dead foetus is reabsorbed and the foetal membrane wraps the foetus The entire structure become brown, black and leathery with moist and sticky surface without odour or exudate In uniparous animals, the mummified foetus is occasionally expelled from the uterus but mostly remained due to the presence of corpus luteum and closed cervix In multiparous animals, the mummified foetus is expelled during parturition together with other normal siblings  In Utero Foetal Death Foetal maceration presence of dead, oedematous foetus or remains of the foetus in the uterus Prerequisite: infection In cases of campylobacteriosis or trichomoniasis, infections affect the stage of early embryo; resorption – no maceration Maceration involves late-stage (>3 months in goats) embryonic death due to non-specific infection and is followed by incomplete maceration where foetal bones remain in the uterus due to the presence of corpus luteum Affected foetus will be oedematous with gas and foul-smelling metritis  Pathology of the Mammary Gland Mastitis inflammation of the mammary glands Affecting all animal species but most important in dairy cattle Bovine mastitis is usually caused by Streptococcus agalactiae although many bacterial and fungal species can cause mastitis Mastitis is uncommonly encountered in cats and dogs  Pathology of the Mammary Gland Mastitis (cont.) Outcome of mastitis: Sub-clinical Clinical but peracute, acute or subacute Outcome of mastitis is depends on: Virulence of the organism Route of infection insulting the ductal system Connective tissue reactions to become oedematous and rapid fibroplasia Occlusion of intralobular ducts leading to stasis of secretion Involution of secretory epithelium in response to stroma  Pathology of the Mammary Gland Types of Mastitis Acute catarrhal mastitis Caused by mild, less virulent organisms Affects individual quarters producing mild systemic response of short duration Leads to reduced, blood-stained secretion that may contain flakes of pus Histologically: slight interstitial oedema pronounced oedema of subcutis at the base of teat Muco-purulent exudate in the cistern and ducts Alveoli are filled with neutrophils  Pathology of the Mammary Gland Types of Mastitis Acute haemorrhagic mastitis Caused by virulent micro-organisms Frequently necrotizing with severe swelling of the affected quarters and systemic reaction that often fatal Produces small amount of secretion that is serosanguinous or fibrinous that may plug the duct and cistern Gland parenchyma is intensely hyperaemic and haemorrhagic Histologically: Necrosis of lobules with surrounding haemorrhages Thrombosis of veins and lymphatics Necrosis may coalesced to involve the entire quarter  Pathology of the Mammary Gland Types of Mastitis Suppurative mastitis Usually caused by Corynebacterium pyogenes and occasionally Pseudomonas aeruginosa Multiple abscesses containing copious, yellow-green pus with foul odour The abscesses: Initiated in the ducts but later spread to adjacent tissues can be palpated and may discharge through the skin  Pathology of the Mammary Gland Types of Mastitis Sub-clinical mastitis The most common type of mastitis Caused by non-specific bacterial infection No clinical sign or gross abnormalities of the udder However, Milk is rejected due to excessive number of leukocytes Histological examination may reveal mild inflammation of the udder  Pathology of the Mammary Gland Mammary gland neoplasms (refer to another lecture notes)