Simultaneous seminoma and interstitial cell tumour in a rabbit with a previous cutaneous basal cell tumour

The development of spontaneous multiple tumours is a rare event in domestic rabbits. The diagnosis of a cutaneous basal cell tumour and the successive development of simultaneous bilateral testicular tumours with dissimilar histology (a seminoma and an interstitial cell tumour) are described in a vasectomized, crossbred dwarf rabbit, aged 6 years. Two cases of basalioma associated with uterine adenocarcinoma have been previously described in rabbits. A similar association between basal cell neoplasia and development of tumours (e.g., testicular and breast cancer) at cutaneous and non-cutaneous sites has been reported in man.

Treatment of aggressive testicular tumors in four dogs

In this report, the authors describe four dogs referred for diagnosis and treatment of unusual and aggressive testicular tumors. For the vast majority of dogs with testicular tumors, orchiectomy is curative. All dogs in this report had surgical resection, and three of four dogs were treated with cisplatin chemotherapy. Cisplatin is widely recognized as the most active agent in testicular cancer in human medicine.

Neoplasia of the male reproductive tract

Genital neoplasms in the male horse are relatively uncommon. Squamous cell carcinomas and squamous papillomas are the most commonly diagnosed neoplasms of the penis and prepuce. Geldings appear to be overrepresented for these types of neoplasms, and accumulation of smegma may be a contributing factor. Early diagnosis and treatment are essential for salvaging these organs before lesions become excessively large and invasive or are allowed to metastasize. Newer treatment modalities such as 5-fluorouracil appear to be promising alternatives to surgical excision. Although generally considered to be uncommon, testicular tumors may occur more frequently than previously thought and have the potential for devastating effects on stallion fertility. Cryptorchidism appears to play a role in the development of equine testicular tumors, especially teratomas. Seminoma is by far the most common testicular tumor of the mature stallion. Seminomas are rapidly growing tumors with a greater potential to metastasize in the horse than in other domestic species. Leydig cell and Sertoli cell tumors have been reported but are relatively rare in the stallion. Orchiectomy is the standard treatment for most testicular tumors. In certain circumstances, however, such as neoplasia occurring in the only functional testis, local cryotherapy of testicular tumors may prolong the breeding career of an affected stallion.

Gastrointestinal adenocarcinomas metastatic to the testes and associated structures in three dogs

Primary testicular neoplasms are common in dogs, but metastases to the testes are rare. Three dogs had enlargement of the testes and associated structures. Upon histological examination, the enlargements were due to metastatic adenocarcinomas. Further examination identified the gastrointestinal tract as the primary site of the metastatic neoplasms in all three cases. The testicular metastases reflected widespread metastatic disease. When metastatic adenocarcinoma is found in the testes and associated structures in dogs, the gastrointestinal tract should be examined closely for a primary tumor site.

Testicular yolk sac carcinoma in a calf

A testicular yolk sac carcinoma (YSCA) was diagnosed in a 28-day-old male Japanese black calf. Macroscopically, the abdominal cavity was filled with reddish gelatinous masses of various sizes. There were no testes in the scrotum or pelvic cavity. Histologically, the masses consisted of the tissues showing a variety of patterns; loose reticular network, pseudopapillary arrangement, festoon, solid nest, and labyrinthine pattern. Tumor cells were round to oval, with single central or polar nuclei with sharply defined nuclear borders and deeply basophilic chromatin. Tumor cells sometimes had glycogen granules, periodic acid-Schiff (PAS)-positive inclusions, or sudanophilic droplets in their cytoplasm. Hyaline matrices were found in extracellular areas and were intensely PAS positive. Immunohistochemically, most of the tumor cells and hyaline matrices had positive reactivity to anti-alpha-fetoprotein and anti-placental-alkaline-phosphatase antibodies. Positive reaction to anti-laminin antibody appeared only in hyaline matrices. This is the first case of a tumor in a domestic animal with histologic and immunohistochemical features analogous to those of human YSCA, endodermal sinus type.

Malignant seminoma with metastasis and herpesvirus infection in a free-living sea otter (Enhydra lutris)

In winter 1990, an adult male sea otter (Enhydra lutris) was found dead along the eastern shore of Prince William Sound, Alaska. Necropsy findings included an enlarged retained left testicle with a twisted spermatic cord, enlarged left sublumbar lymph node, emaciation, dental attrition, oral papules and ulcers, and luminal intestinal hemorrhage associated with numerous acanthocephalids. A malignant seminoma was present in the left testicle and left sublumbar lymph node. Additionally, herpesvirus like intranuclear inclusion bodies were found in oral, esophageal, and corneal epithelial cells. Virions consistent with a herpesvirus were found in esophageal epithelium. Dental attrition, severe intestinal acanthocephaliasis, the malignant seminoma, and emaciation were considered contributing factors in causing death. The herpesviral disease was probably secondary to the debilitation and stress. This is the first report of malignant seminoma with metastasis in a sea otter.

Carcinoma in situ and seminoma in equine testis

The presence of atypical germ cells resembling carcinoma in situ of human testis is reported for the first time in an unilaterally cryptorchid stallion. These cells were found in association with developing intratubular seminoma indicating they represented carcinoma in situ.

Testicular fine needle aspiration cytology as a diagnostic tool in dog infertility

The results of testicular aspirate cytology taken from clinical patients with a history of infertility were compared with the clinical and histological findings. Azoospermia was the most common and the most rewarding indication for the examination. Samples were also taken from cases with suspected testicular tumours, orchitis, epididymitis, severe oligo- and teratozoospermia, lack of libido and unilateral testicular atrophy. Histological and cytological findings were found to correlate well. Identification of cell types from normal germinal epithelium was relatively easy. No immediate adverse effects of aspiration were noted. Five normospermic dogs were monitored for two to six months after aspiration, and there were no marked deleterious effects on testicular consistency, testicular histology or semen characteristics. Testicular cytology obtained by fine needle aspiration may, at least to some extent, be used to assist clinical diagnosis, especially in azoospermic dogs and dogs with palpable changes of testicular tissue.

Influence of orchiectomy on canine behaviour

One hundred and twenty-two dog owners were interviewed to obtain information about the effects of orchiectomy on the behaviour, unwanted side effects, and testosterone-dependent disease processes in their dogs. Behavioural problems were the main reason for orchiectomy, unwanted sexual behaviour being the most common, together with roaming, aggression, and abnormal urination behaviour. Objectionable sexual behaviour, inter-male aggression, roaming, and abnormalurination were reduced after orchiectomy in approximately 60 per cent of the dogs. The side effects of orchiectomy included increased bodyweight, increased appetite and decreased activity in less than 50 per cent of the dogs, and there was a significant relationship between increased appetite and bodyweight. The clinical signs of testosterone-dependent disease in most of the dogs either decreased or disappeared after orchiectomy.

A spontaneous testicular teratoma in an ICR mouse

A spontaneous teratoma was detected in the left testis of a 7-wk-old male ICR (Crj:CD-1) mouse. The tumor was composed of a variety of well-differentiated tissue elements from all 3 germ layers including neuronal tissue and stratified epithelium as ectoderm-derived tissues, bone, cartilage, striated muscle, and adipose tissue as mesodermal tissues, and respiratory columnar epithelium as endoderm-originated tissue. No tumor metastasis was detected. It may be of congenital origin as in strain 129 mice. To the best of our knowledge, this is the first report concerning spontaneous testicular teratoma in a strain ICR mouse.

Spontaneous Leydig cell tumors in inbred laboratory mice

Six Leydig cell tumors were identified in 6,500 male mice necropsied over a period of 8.5 years. All tumors developed spontaneously in BALB/cJ and BALB/cByJ inbred mice. When submitted for necropsy, affected mice were 8 to 9 months old. The incidence was calculated to be 5.5 per 100,000 males retained as breeders. Tumors were unilateral, with no predilection for right or left testis, Histologically all Leydig cell tumors were well differentiated and of the solid, diffuse type.

[Testicular tumors in dogs: a literature review]

The incidence of testicular tumours in dogs is higher than in other species. The main three types are: Sertoli cell tumour, seminoma, and Leydig cell tumour. Metastases are rare. Sertoli cell tumours, and to a lesser extent Leydig cell tumours, are often associated with feminization, which occurs in 19% and 5% of cases, respectively. Seminomas are rarely associated with feminization. Feminization seems to be the result of an excessive oestrogen production by the tumour. In severe cases this may lead to bone marrow depression. Atrophy of the contralateral testis is a common finding. It is not clear whether this is a result of feminization or of age because most tumours occur in older dogs. By investigating the morphology of the testis, and the endocrinological and fertility status of the dog this phenomena is hopefully going to be explained. Extra attention is given to the pathogenesis of feminization.

Proliferative lesions of the testis in ad libitum-fed and food-restricted Fischer-344 and FBNF1 rats

The effect of 40% food restriction on spontaneous proliferative lesions of the testis was evaluated in lifetime and cross-sectional (serial sacrifice) studies of 419 Fischer (F-344) and 304 Fischer x Brown Norway (FBNF1) male rats. Interstitial cell hyperplasia and interstitial cell adenoma (ICA) were the most common proliferative lesions in each genotype; incidence of each was less in the FBNF1. In each genotype, food restriction delayed the onset of both lesions and reduced the incidence of ICA. At 12 months interstitial cell hyperplasia was present in 11 of 12 ad libitum (AL)-fed and 0 of 12 food-restricted (FR) F-344 rats. In FBNF1 rats interstitial cell hyperplasia was observed first at 18 months in AL-fed and at 36 months in FR groups. Interstitial cell adenoma developed in 5 of 12 AL-fed F-344 rats by 18 months and in 2 of 12 FR rats by 24 months; 2 of 12 AL-fed FBNF1 rats had ICA at 30 months, and 1 of 12 FR rats had ICA at 42 months. In these cross-sectional studies approximately half the ICA cases in F-344 rats were bilateral; no FBNF1 rats had bilateral ICA. In lifetime studies the incidence of ICA was reduced from 49% in AL-fed rats to 19% in FR F-344 rats and from 9% in AL to 4% in FR FBNF1 rats. The incidence of mesothelioma was low in both genotypes and was not obviously altered by food restriction. A malignant embryonal neoplasm, an unclassified benign neoplasm, and three seminomas were present in the testes of FBNF1 rats.

Ultrasonographic diagnosis of non-palpable Sertoli cell tumours in infertile dogs

Three previously fertile dogs were examined with a history of recent infertility. Semen evaluation revealed marked spermatozoal abnormalities, including lesions of the mid-piece region, poor spermatozoal motility and a low total spermatozoal output. The mean number of live normal spermatozoa was 21.1 +/- 17.4 x 10(6) spermatozoa. Examination of the testes with diagnostic B-mode ultrasound demonstrated solitary mass lesions which in each case were not palpable. Plasma oestrogen concentrations were elevated (mean, 43.0 +/- 8.5 pg/ml), and histologically the masses were shown to be Sertoli cell tumours. Several months after unilateral orchidectomy there was an increase in the percentage of normal spermatozoa and an increase in the spermatozoal motility and total spermatozoal output. The mean number of live normal spermatozoa was 149.8 +/- 22.9 x 10(6) spermatozoa and all the dogs subsequently returned to fertility. Ultrasonographic examination of the testes should be considered part of the routine investigation of the male reproductive tract.

Nuclear bodies appearance rate in canine testicular Sertoli cell tumor

A number of nuclear bodies (NB) were observed in the canine testicular Sertoli cell tumors (SCT). We statistically examined nineteen cases of canine SCT concerning the NB appearance rate (NBAR), and also examined the NBAR in four cases of the normal testicular Sertoli cells. The mean value of the total number of the NBAR of SCT was significantly higher than that of normal Sertoli cells. The SCT were classified into three groups according to the Nielsen and Lein's histological classification (1974): intratubular SCT without invasion, intratubular SCT with invasion, and diffuse type SCT. The mean value of NBAR of the diffuse type SCT was significantly higher than that of the intratubular SCT with and without invasion, and there was no significant difference between the mean values of NBAR of the latter two groups. The distribution of NBAR of the diffuse type SCT was significantly different from that of the intratubular SCT with and without invasion. On the other hand, the individual differences of NBAR of the diffuse type SCT and the intratubular SCT with invasion was significantly higher than that of the intratubular SCT without invasion. The present study suggests that the increase of NBAR in canine SCT might be correlated with the tumor invasive progression.

Laminin expression in testicular tumours of the dog

The expression of laminin was studied to determine the distribution pattern of basement membranes (BMs) in normal testes and in a series of 40 canine testicular tumours (seminomas, Leydig and Sertoli cell tumours). BM was always present around seminiferous tubules and blood vessels in normal testes and in seminomas and Sertoli cell tumours of the intratubular type without invasion. BM changes (fragmentation or loss, or both) were usually found in invasive neoplasms which retained their tubular structure; disruption or absence was observed in tumours, with a diffuse pattern. The BM was never expressed in Leydig cell tumours, except around vessels, irrespective of their histological growth pattern (cystic-vascular, pseudoadenomatous, diffuse). An attempt was made to relate the degree of BM modification to proliferative monoclonal antibodies and mitotic index. In parallel with the progressive loss of BM an increase in proliferative activity occurred, indicating that BM changes are additional useful prognostic indicators in testicular tumours of the dog.