Gynecomastia and mammary gland adenocarcinoma in a Nubian buck Anne A. Wooldridge, Marjorie S. Gill, Thomas Lemarchand, Bruce Eilts, H. Wayne Taylor, Timm Otterson

Abstract A 6-year-old Nubian buck was presented for bilateral mammary gland enlargement. Gynecomastia and mastitis were diagnosed, and bilateral mastectomy was performed. Histological examination showed mammary adenocarcinoma, active lactation, hyperplasia, and abscessation. Karyotyping showed a normal male. Clinical, therapeutic, etiologic, and epidemiologic aspects of gynecomastia and mammary gland adenocarcinoma are discussed.

Resume Gynecomastie et adenocarcinome mammaire chez un bouc nubien. Un bouc nubien de six ans a ete refere pour un elargissement bilateral de la glande mammaire. Apres un diag- nostic de gynecomastie et de mammite, une mastectomie bilaterale a ete effectuee. L'histopatholo- gie revela un adenocarcinome mammaire, une lactation active, de l'hyperplasie et la formation d'abces. Le caryotype etait celui d'un male normal. La discussion porte sur les aspects cliniques, therapeu- tiques, etiologiques et epidemiologiques de la gynecomastie et de l'adenocarcinome mammaire. (Traduit par docteure Alice Bouffard) Can Vet J 1999; 40: 663-665

A6-year-old Nubian breeding buck was presented blood cell count and serum biochemical analysis were for evaluation of bilateral mammary gland enlarge- within normal limits. Opaque, bloody, flocculent fluid ment of several months' duration. Intermittent enlarge- obtained from an aspirate of the right gland revealed neu- ment of the udder began 3 y prior to presentation. The trophilic inflammation. Percutaneous ultrasonography udder had increased and decreased in size approxi- was performed on the right mamma using a 10.0 MHz mately 5 times during this period. The owner expressed real-time linear array scanner. The mamma was normal appearing milk from both teats during the approached from multiple portals due to its pendulous episodes of enlargement; bloody, purulent material was shape, so the entire mass was evaluated ultrasono- expressed from the teats on one occasion. No treat- graphically. Multiple, rounded, 2-cm, anechoic regions ment was attempted during any of these episodes, and the surrounded by echogenic tissue were noted. Strong udder eventually returned to normal size each time. acoustic shadowing emanated from multiple hyper- Results of a breeding soundness examination performed echoic foci interspersed throughout the more normal 2 y prior to presentation showed the buck to be a satis- appearing mammary tissue. Abscessing mastitis with foci factory potential breeder. Historically, the subject had of caseous material was suspected after viewing the sired several progeny during breeding seasons that were ultrasound images. The ventral portion of the right concurrent with the udder enlargement. The last record gland was infiltrated with 2% lidocaine and lanced. of successful breeding was 1 mo prior to his presentation. A large amount of yellow fluid containing aggregates of He had lost weight in the preceding 2 mo and was hav- caseated material was drained from the gland. This ing difficulty ambulating due to the pendulous udder. material, submitted for bacteriologic culture and sensi- On physical examination, the goat was bright, alert, tivity testing, yielded Escherichia coli, Corynebacterium and in fair body condition (100 kg). He did not resent pal- spp., and Staphylococcus spp. Due to the severe masti- pation of the udder. The left mamma was slightly tis in the right mamma and the discomfort caused by the enlarged and firm, and a clear, yellow secretion could be size of the gland, the owner elected bilateral mastectomy. expressed from the teat. The right mamma, signifi- The goat was anesthetized and both mammary glands cantly larger than the left, measured approximately were surgically removed. During surgery, it was noted 20 cm in diameter and was pendulous, but no secretions that the right mammary/scrotal lymph node was enlarged; could be expressed from the teat. The goat circum- however, the node was not resected. The goat recovered ducted the right hind limb as a result of the pendulous uneventfully from anesthesia and had no postoperative mammary gland. The testes were normal in texture but complications. Procaine penicillin G was administered, small in size. No other significant abnormalities were 3 000 000 IU, SC, ql2h for 5 d. Histological examina- observed on physical examination. Results of a complete tion revealed low grade adenocarcinoma in both glands (Figure 1), active lactation, fibroadenomatous hyper- plasia, and abscessation. Adenocarcinoma was evi- Department of Veterinary Clinical Sciences (Wooldridge, denced by invasion of the lactating parenchyma by Gill, Eilts, Otterson); Veterinary Pathology (Lemarchand, nodules composed of tubules and cords of neoplastic Taylor), School of Veterinary Medicine, Louisiana State epithelial cells separated by a large amount of immature University, Baton Rouge, Louisiana, USA. connective tissue (Figure 1). The epithelial cells exhib- Address correspondence to Dr. Anne Wooldridge. No reprints ited moderate variation in nuclear size, shape, and will available from the authors. chromatin pattern, prominent nucleoli, and infrequent

Can Vet J Volume 40, September 1999 663 levels (4). Conditions that affect the endocrine balance in the goat, such as hypophyseal, testicular, or adrenal W*~~~~~~~~~~~ ~ abnormalities, could be associated with gynecomastia (4). An adrenal cortical adenoma was found in a castrated goat with gynecomastia and lactation. This goat had high circulating levels of estrodiol 17, prolactin, growth hormone, and cortisol as compared with his clinically normal twin (5). Continuous manipulation of the rudimentary teats in the buck has also been incriminated as a cause of pro- gressive udder enlargement and eventual lactation (1). Mechanical stimulation, produced by milking devel- oped glands in the buck, may result in gradual enlarge- ment, and infection may serve to further aggravate the condition (6). Fertile male goats demonstrating gynecomastia may eventually show decreased libido and semen quality (4). A Nubian buck with unilateral gynecomastia and mastitis had soft testes, decreased sperm count and motility, and low serum testosterone. Postmortem exam- ination revealed calcification of the testicles and no female genitalia (6). Reports of mammary gland carcinoma in food animals are rare (3,7-9). A steer with gynecomastia and masti- tis was reported to have adenocarcinoma in the mammary glands, but a karyotype was not performed (3). Udders from 220 female goats were evaluated histologically, and 3 intraductal carcinomas were found, one of which had metastasized to the mammary lymph node (7). Another study reported 6 neoplasms out of 3693 female goat Figure 1. Mammary adenocarcinoma from a male goat. Cords gln dvlomntwthu rdce eriit.Iti ps udders; 3 of these were adenocarcinoma (8). A Toggenberg and tubules of neoplastic cells locally invade the adjacent doe had mammary adenocarcinoma and a granulosa cell arrow). They are sep- secretingtulate httesmammary parenchymanmlav(longnraedpouto tumor with no metastasis. It was speculated that increased arated by immature fibroplasia infiltrated with predominantly was smallofhroe?ricesdrsoslymphocytes. Papillary projectionsonra(short arrow)omnare estrogen secretion from the granulosa cell tumor within the tubular structures. Bar = 300 ,um. Stained with involved in the formation of the mammary tumor (9). hematoxylin and eosin. To our knowledge, this is the first case of adenocar- cinoma of the mammary glands reported in a buck. A chromosomal analysis was performed on 50 spreads mitoses (0.2 mitoses per 400X magnification). Cells prepared from lymphocytes and revealed a normal male often retained polarity. caprine karyotype (60, XY). One theory for the cause Gynecomastia, or well-developed male mammary of the gynecomastia in this goat was hereditary pre- glands with secretory activity, is fairly common in disposition; he originated from a line of high producing bucks. It is occasionally seen in ramns and dogs, and rarely dairy goats and his grandsire reportedly developed in bulls (1). Mammary gland development is certainly gynecomastia and subsequently died of mastitis. Another seen in hermaphrodites but is also observed in fertile possibility is that the condition may have been trig- male animals. Causes of gynecomastia in fertile males gered by hormonal dysfunction or dysregulation. The include chromosomal abnormalities, familial predis- long history of intermittent udder enlargement and mas- position, and hormonal or mechanical effects. A fertile titis and the good general physical condition of the buck that produced 20 mL of milk daily was deter- Nubian buck in this report suggest that the tumor was mined to be a chromosomal mosaic with variable dele- slow to develop and grow. The owners indicated that 1 y tions of the Y chromosome (XO/XY) (2). Another case after discharge from the hospital, the buck was in excel- report cited a buck that produced 250-300 mL of milk lent physical condition, had no apparent tumor regrowth per day and had a normal phenotype and typical male in the mammary area, and had successfully sired a set of behavior; however, 45% of the neutrophils had sex twins. cvi chromatin (Barr body). Sex chromatin in neutrophils indi- cates an extra X chromosome, but karyotyping was not performed in that animal (3). References A familial predisposition to gynecomastia has also 1. Heidrich HJ, Renk W. Anomalies of lactation. In: Diseases of the been observed. Males from high milk producing lines of Mammary Glands of Domestic Animals. Translated by LW vanden manifested Heever. Philadelphia: WB Saunders, 1967: 37-46. British Saanens have reportedly mammary 2. Rieck GW, Hohn H, Loeffler K, Marx D, Bohm S. Gynakomastie bei einem Ziegenbock. II. Zytogeneticsche Befunde: XO/XY - Mosaik mit variablen Deletionen des Y-Chromosoms. Zuchthyg 1975; 10: 159-168.

664 Can Vet J Volume 40, September 1999 3. Panchadevi SM, Pandit RV. Milking males - two case studies. 7. Singh B, Iyer PKR. Mammary intraductal carcinoma in goats. Indian Vet J 1979; 56: 590-592. Vet Pathol 1972; 9: 441-446. 4. Smith MC, Sherman DM. Goat Medicine. Philadelphia: Lea & 8. Sulaiman MY, Al-Sadi HI. The descriptive epidemiology of udder Febiger, 1994: 446-463. lesions in Northern Iraqi ewes. Prev Vet Med 1992; 13: 299-304. 5. Lofstedt RM, Laarveld B, Ihle SL. Adrenal neoplasia causing lac- 9. Cooke MM, Merrall M. Mammary adenocarcinoma and granu- tation in a castrated male goat. J Vet Int Med 1994; 8: 382-384. losa cell tumour in an aged Toggenberg goat. N Z Vet J 1992; 40: 6. Dafalla EA, Ramadan RO, Gameel AA, Galil AKA, Alhendi AB, 31-33. Moudawi MM. A functioning udder in a male goat. Zentrabl Veterinarmed A 1990; 37: 686-691.

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