Testicular Neoplasms (Interstitial and Sertoli Cell Tumours) in a Domestic Ferret (Mustela putorius furo)

Unilateral testicular enlargement was detected in a 5‐years‐old domestic ferret during a routine sterilization. The right testicle showed two different types of proliferative lesions: (i) round nodules, well demarcated, showing a soft yellow tissue; (ii) white nodules, firm, with irregular‐shaped invaginations. Microscopically, the neoplastic proliferations were identified as an interstitial neoplasm and Sertoli cell tumour, respectively. The left testicle was small and showed intense testicular atrophy. Clinical evaluation of the ferret did not show any other apparent pathological processes. This study is the first case reporting the concomitant occurrence of a Sertoli cells tumour and an interstitial cell tumour in a domestic ferret.     

Malignant Mixed Sex Cord-stromal Tumour in a Stallion

A 30-year-old Standardbred stallion was examined for unilateral scrotal swelling. Physical and ultrasound examinations revealed a painless enlarged left testis with a non-homogeneous echogenicity, when compared with the controlateral testis. The stallion underwent left unilateral orchiectomy. Grossly, the excised testis was irregularly enlarged (12 x 9 x 9 cm; weight: 530 g) and firm. The sections showed that testicular parenchyma was replaced by a lobulated, greyish-white mass, which involved the epididymal head. At microscopy, a dual Leydig and Sertoli cell tumour component could be seen. Neoplastic Sertoli cells were prevalent and presented pleomorphic cells, mitotic figures and occasional vascular invasion. Tumour patterns showed tubular and solid areas, cord-like or diffuse in appearance, among which newly formed Leydig cell nests and low-density fibrillar bundles were interposed. Immunohistochemically, a weak to moderate immunostaining for vimentin, AE(1)/AE(3) cytokeratin, alpha-1-antitrypsin and CD99 antigens was found in the growing Sertoli cells, whose nuclear MIB-1 labelling index scored 13 +/- 2%. The Leydig tumour cells, on the other hand, displayed a moderate to strong positivity for alpha-inhibin, vimentin, AE(1)/AE(3) cytokeratin, neurone-specific enolase and CD99. On the basis of these findings, a diagnosis of malignant mixed sex cord-stromal tumour was made.     

Canine hypertrophic osteoarthropathy associated with a malignant Sertoli cell tumour

A 15-year-old crossbred dog was presented with a severe cough of acute onset and an enlarged right testis. Symptomatic treatment for presumed 'kennel cough' failed to produce any improvement and at re-examination the dog had developed a swollen right forelimb. Radiographic examination suggested a diagnosis of hypertrophic pulmonary osteoarthropathy (Marie's disease) associated with pulmonary metastases from a testicular tumour. The dog was re-presented five days later with acute-onset severe vomiting and the owner elected for euthanasia. Necropsy was performed and histopathological assessment confirmed the presence of a Sertoli cell tumour in the right testis with multiple pulmonary and renal metastases. Hypertrophic pulmonary osteoarthropathy is a rare complication of metastatic canine Sertoli cell tumour. The authors know of no previously reported cases.     

Sertoli cell tumour with Call-Exner-like bodies in a dog

An histological diagnosis of Sertoli cell tumour and concurrent seminoma was formulated after complete resection of the right testicle in a 8-year-old Doberman. The unusual histological feature of abundant eosinophilic material with a extracellular location forming the Call-Exner-like bodies is reported.     

A seminoma in a monorchid guinea fowl (Numida meleagris)

A case of seminoma in a monorchid adult guinea fowl (Numida meleagris) is described. Grossly, a right enlarged testis, which was soft in consistency, and white to pale in colour with few spots of haemorrhages was observed. Histologically, the testicle revealed diffusely spread sheets of tumour cells. The cells were large pleomorphic with eccentrically placed hyperchromic nuclei. Mitotic figures were evident. A scanty fibrous stroma, containing lymphocytes and histiocytes, separating the groups of tumour cells, along with few areas of haemorrhages were observed. Occurrence of seminoma in guinea fowl is unusual and hence reported.     

B‐cell lymphoma with Mott cell differentiation in a cat

A 12‐year‐old, male castrated Domestic Shorthair cat was presented to Animal Medical Center of Gifu Univeristy with anorexia and vomiting. Physical examination revealed an enlarged left tonsil and right mandibular lymph node (approximately 2–3× the normal size), and a submucosal mass on the right side of the epiglottis (1.5 × 2.0 cm). On computed tomography images, an enlarged left tonsil, and enlarged right mandibular, right pharyngeal, and left and right cervical lymph nodes were observed. Cytologic examination of smears of tonsil and lymph nodes revealed numerous medium‐ to large‐sized neoplastic lymphoid cells, approximately half of which contained one or several light‐blue homogenous globoid cytoplasmic inclusions (5–10 μm), which stained magenta with periodic acid–Schiff (PAS) stain. Histopathologic examination of the left tonsil revealed diffuse proliferation of medium‐ to large‐sized neoplastic lymphoid cells effacing the original lymphoid architecture. Half of the cells contained one or several eosinophilic globoid cytoplasmic inclusions, which stained magenta with PAS and showed positive immunohistochemical reactions for immunoglobulin M (IgM) and λ light chain. Neoplastic lymphoid cells were also CD20⁺, Pax5⁺, and MUM1⁺, and CD3^?. Thus, the neoplastic lymphoid cells expressed a B‐cell immunophenotype, and the globoid cytoplasmic inclusions represented an aberrant IgM λ light chain accumulation, similar to Russell bodies. B‐cell lymphoma with Mott cell differentiation was diagnosed based on cytologic, histopathologic, and immunohistochemical features. This is the first report of B‐cell lymphoma with Mott cell differentiation in a cat.     

Endocrinological characterization of an ovarian sex cord–stromal tumor with a Sertoli cell pattern in a Japanese Black cow

A Japanese Black cow was evaluated for prolonged post‐partum anestrus and enlargement of the right ovary. Transrectal ultrasonography revealed that the right ovary was markedly enlarged and had a solid appearance, while the left ovary was small and inactive. The presumptive diagnosis was directed towards granulosa‐theca cell tumour (GTCT) which was supported by markedly elevated plasma anti‐Müllerian hormone (AMH; 332.0 ng/ml), oestradiol (E₂; 103.3 pg/ml) and immunoreactive inhibin (ir‐INH; 2.1 ng/ml) in comparison with the diagnostic cut‐off points for bovine GTCTs. Since the cow had been infertile and had swelling of the udder, slaughter was chosen. Histopathological examination revealed that the tumour was an ovarian sex cord–stromal tumour (SCST) with a Sertoli cell pattern. These findings suggest that plasma AMH, ir‐INH and E₂ could be possible biomarkers for bovine ovarian SCST with a Sertoli cell pattern, whereas this case could not be distinguished from GTCTs based on endocrinological profile.     

Malignant Sertoli cell tumor in the retained abdominal testis of a unilaterally cryptorchid horse

A 13-year-old Morgan gelding was evaluated because of a mass in the caudal region of the abdomen. The horse had been presumed to be a gelding, but necropsy findings revealed a retained testis in the right retroperitoneal space. Histologically, the retained testis contained neoplastic cells; metastases were identified in the liver, spleen, lungs, and sublumbar lymph nodes. Immunohistochemical examination of the testis and metastatic tissues confirmed the diagnosis of malignant Sertoli cell tumor. Testicular neoplasms are infrequently reported in stallions. Seminomas are most commonly reported, whereas Sertoli cell tumors are considered to be rare. Typical biological behavior of Sertoli cell tumors in horses is unknown. To the authors' knowledge, there have been 2 reports of Sertoli cell tumors in horses; the tumors developed in descended testes, and 1 tumor was malignant.     

Persistent Mullerian Duct Syndrome in a Miniature Schnauzer Dog with Signs of Feminization and a Sertoli Cell Tumour

A 5‐year‐old male Miniature Schnauzer was presented with unilateral cryptorchidism and signs of feminization. Abdominal ultrasonography revealed an enlarged right testis and a large, fluid‐filled cavity that appeared to arise from the prostate. Computed tomography revealed the cavity to be consistent with an enlarged uterine body, arising from the prostate, and showed two structures resembling uterine horns that terminated close to the adjacent testes. The dog had a normal male karyotype, 78 XY. Gonadohysterectomy was performed and both the surgical and the histological findings confirmed the presence of a uterus in this male animal, resulting in a diagnosis of persistent Mullerian duct syndrome (PMDS). The enlarged intra‐abdominal testis contained a Sertoli cell tumour. Computed tomography proved to be an excellent diagnostic tool for PMDS.     

Sertoli cell tumour in a cat

A Sertoli cell tumour occurred in a cryptorchid testis of a 1-year-old cat with no signs of feminization. The tumour showed intratubular growth without interstitial infiltration and the neoplastic cells appeared polymorphous and vacuolated. Mitotic figures were rare. The diagnosis was based on histopathological, ultrastructural and immunohistochemical features of the tumour cells.     

A case of feline primary inflammatory mammary carcinoma: clinicopathological and immunohistochemical findings

The clinicopathological and immunohistochemical findings of a primary feline mammary tumour with features similar to human and canine primary inflammatory carcinoma are described for the first time. The cat presented to the clinic for the rapid onset of oedema, severe erythema, local pain and warmth of the inguinal region, with a pustular-to-nodular cutaneous lesion in association with an ill-defined underlying mass. An epithelial malignant tumour was diagnosed by cytological investigation. Necropsy revealed a thickening of the skin with oedema of the subcutis in the right inguinal area, and regional and distant metastases. Histology showed an unencapsulated tubulopapillary proliferation of malignant epithelial cells, with a massive embolisation in the dermal lymphatics and a mild inflammatory infiltrate. Through immunohistochemistry, the tumour was found to be oestrogen (ER)-alpha-, androgen (AR)- and progesterone (PR)-negative; neoplastic cells were ER-alpha, AR-negative and focally PR-positive. An irregular, mild and focal HER-2 immunoreactivity was present (score +1, non-HER-2 overexpressing). The neoplastic cells were cyclo-oxygenase-2 and vascular endothelial growth factor positive.     

Malignant fibrous histiocytoma (giant cell type) associated with a malignant mixed tumor in the salivary gland of a dog

A 12-year-old male Boxer dog presented with a 5 x 5 x 7-cm partially encapsulated mass in the right mandibular salivary gland. Histologically, the mass was composed of neoplastic epithelial and mesenchymal cells. The mesenchymal component consisted of two cell populations arranged in different patterns: coalescing nodules of neoplastic mononuclear cells with rare osteoid and numerous osteoclastlike giant cells; and sheets of neoplastic spindle cells intermingled with neoplastic epithelial cells and containing osteoid and well-formed bone trabeculae lined by osteoblasts and few osteoclastlike giant cells. On the basis of these histological features, two malignant salivary tumors were diagnosed: a malignant fibrous histiocytoma (giant cell type) and a malignant mixed tumor. Immunohistochemical studies demonstrated keratin 5 and 8 expression by the neoplastic epithelial cells, indicating a probable salivary ductal origin, and vimentin expression by all mesenchymal elements, suggesting a fibroblastic line of differentiation.     

Bilateral Sertoli and Interstitial Cell Tumours in Abdominal Testes of a Goat with Polled Intersex Syndrome (PIS)

An 8‐year‐old, mixed breed, polled goat was presented for evaluation of male‐like behaviour. Clinical findings included clitoromegaly, a heavily muscled neck, pronounced beard, and erect dorsal guard hairs, which are phenotypic characteristics commonly observed in intersex animals. Transrectal ultrasonography revealed the presence of two abdominal masses caudolateral to the uterine horns. Serum concentration of estradiol was elevated. Genetic evaluation was compatible with polled intersex syndrome defined by an XX karyotype without a Y chromosome or SRY gene. Based on gross and histologic evaluation, the abdominal masses were determined to be intra‐abdominal testes, each of which was effaced by Sertoli cell and interstitial (Leydig) cell tumours. The Sertoli cell tumours (SCTs) represented two unique histologic patterns. Regardless of pattern, neoplastic Sertoli cells were consistently lipid laden and positive for vimentin. Interstitial cell tumours (ICTs) were negative for vimentin. Clinical and histopathologic findings suggest that prolonged exposure to steroids secreted by neoplastic Sertoli cells contributed to virilization. In addition, results from immunohistochemistry indicated that vimentin may be a valuable immunodiagnostic tool for differentiation between interstitial and Sertoli cell tumours in goats.     

Intra-abdominal torsion of a neoplastic testicle in a rabbit (Oryctolagus cuniculus) with cryptorchidism

Background: Testicular torsion is a relatively common complication of cryptorchidism in domestic mammals but is currently unreported in rabbits. Case presentation: A 7-year-old Dutch rabbit was examined for sudden anorexia and lethargy. The rabbit was previously diagnosed with unilateral cryptorchidism 5 years earlier; however, the owner declined surgical treatment at that time. Transabdominal ultrasonography showed a structure consistent with an enlarged testis, with decreased echogenicity, and absent blood flow upon color Doppler ultrasonography. After induction of general anesthesia and during preparation for surgery, the patient had an episode of cardiac arrest. After successful resuscitation, bilateral cryptorchidectomy continued as planned. A ventral midline laparotomy was performed and confirmed presence of an enlarged, dark red left testicle torsed on its spermatic cord. The contralateral testicle was atrophic. Both testicles were removed after standard hemostasis. Recovery was uncomplicated. Histopathologic examination revealed a diagnosis of Sertoli cell tumor and extensive hemorrhage and necrosis in the torsed testicle. Conclusions and Clinical Relevance: Based on literature search, this is the first reported case of intra-abdominal torsion of a neoplastic testicle in a cryptorchid rabbit. Early elective cryptorchidectomy before the potential development of life-threating complications may be beneficial in rabbits as in other species.     

Intratesticular benign peripheral nerve sheath tumour in a ferret (Mustela putorius furo)

A domestic ferret was submitted for sterilisation because of right testis enlargement. Oestradiol and cortisol concentrations were within normal physiological ranges, but testosterone was below and progesterone above normal. Microscopically, the right testis, with the exception of a small part of the epididymis, was replaced with neoplastic tissue. The tumour was composed of streams and bundles of closely packed spindle to ovoid cells forming whorls around collagen and capillaries, and separated by a collagenous matrix. In some areas, cells were loosely arranged and separated by a pale myxomatous matrix. The left testis showed atrophy. The majority of neoplastic cells expressed vimentin and S-100 protein, while expression of collagen IV was moderate and there was no expression of glial fibrillary acid protein. On the basis of macroscopical and histopathological findings, and supported by immunohistochemical reactivity, the diagnosis of benign peripheral nerve sheath tumour was made. This is the first report of benign peripheral nerve sheath tumour in ferret testis.     

Progressive neurological signs associated with systemic mastocytosis in a dog

A 9-year-old dog was presented with nonregenerative anaemia and severe thrombocytopenia, diarrhoea, spinal hyperalgesia and progressive hindlimb paresis. A moderately well differentiated cutaneous mast cell tumour (MCT) was removed from the skin of the right elbow along with the enlarged right prescapular lymph node. Due to deterioration of the dog's neurological condition, euthanasia was performed. On necropsy examination, haemorrhage and accumulations of poorly differentiated mast cells were found in the lumbosacral region and cauda equina. This article describes an unusual presentation of systemic mastocytosis and the previously unreported finding of metastasis of mast cells to the spinal cord.     

Use of Contrast‐Enhanced Ultrasonography in Chronic Pathologic Canine Testes

Contrast‐enhanced ultrasound with sulphur hexafluoride microbubbles was performed in seven healthy dogs without a history of reproductive pathology and with histologically confirmed normal testes and in 42 dogs with chronic scrotal anomalies. All dogs underwent orchiectomy and histological examination. Enhancement patterns and perfusion parameters (peak intensity and regional blood flow) of testes of healthy dogs and testes with chronic lesions were compared. Fourteen non‐pathologic and 60 pathologic testes were considered. Forty testes were neoplastic (24 interstitial cell tumours, 9 seminomas, 7 Sertoli cell tumours), 20 were non‐neoplastic (16 testicular degenerations, 2 chronic orchitis, 1 testicular atrophy, 1 interstitial cell hyperplasia). In healthy dogs, the contrast medium flow had a rapid homogeneous wash‐in and wash‐out, with a short peak phase. With contrast ultrasound, testes that were inhomogeneous with a hyperenhancing pattern were associated with neoplasia (sensitivity: 87.5%, specificity: 100%). Lesions with persistent inner vessels and a hypo‐to‐isoechoic background were significantly associated with seminomas (sensitivity: 77.8%, specificity: 100%). Testes with non‐neoplastic lesions were characterized by a scant/moderate homogeneous enhancement. Perfusion parameters were higher in neoplastic lesions. Contrast ultrasound was a feasible diagnostic tool in the assessment of testicular lesions, with hyperenhancement being an important feature in the diagnosis of malignancy.     

Testicular neoplasia in the retained testicles of an intersex male dog

This case describes the presentation and management of an 8 yr old phenotypically female intersex male dog presented for evaluation of a mass in the right inguinal region. The right inguinal space was surgically explored, and a large irregular mass resembling a fully developed testicle was identified in the right vaginal tunic. A second mass resembling an atrophied, but anatomically mature testicle, was identified in the left tunic. The larger mass was identified as a Sertoli cell tumor that had replaced all normal testicular tissue. The smaller mass was identified as a testicle that contained a small intratubular seminoma. The patient was diagnosed as having a phenotypic female sex, chromosomal male sex, and a gonadal male sex. Hormone assays completed before and after the gonadectomy and mass removal document an elevation of circulating progesterone presurgically that returned to baseline by 1 mo postsurgically. The source of the progesterone was identified to be the Leydig cells of the atrophied testicle.     

A spontaneously occurring malignant ovarian Sertoli cell tumor in a young Sprague Dawley rat

Primary ovarian tumors are generally uncommon in rats used in toxicologic studies. A malignant Sertoli cell tumor was present in the ovary of a 19-week-old female Sprague Dawley rat. Macroscopically, the mass was white and firm, 10 × 13 × 17 mm in size, and located in the right ovary. Histopathologically, the mass was composed of nests of pleomorphic cells, which formed seminiferous-like tubules separated by a thin fibrovascular stroma. The tubules were lined by tumor cells, which had basally located nuclei and abundant eosinophilic and vacuolated cytoplasm. In some areas, the tumor cells were arranged in a retiform growth pattern, mimicking a rete testis/ovarii. Disseminated metastases to the surfaces of the mesentery, spleen and liver were also present. Immunohistochemically, many tumor cells were strongly positive for vimentin, estrogen receptor α and Ki 67. Some tumor cells were positive for pancytokeratin and inhibin α. These findings closely resemble those of an ovarian-derived human malignant Sertoli cell tumor. From our review of the literature, we believe this is the first report of a spontaneous malignant Sertoli cell tumor in the ovary of a young laboratory rat. This case might provide useful historical control information for rat toxicity studies.