Feline necrotising sialometaplasia: a report of two cases

Unilateral swelling of submandibular salivary gland in two cats was diagnosed as necrotising sialometaplasia. Histological features that differentiate the disease from other salivary gland lesions, particularly neoplasia are: lobular necrosis of salivary tissue; squamous metaplasia conforming to duct and/or acinar outlines; preservation of salivary lobular morphology; and variable inflammation and granulation tissue.     

Pathogenesis of sialodacryoadenitis in gnotobiotic rats.

The pathogenesis of sialodacryoadenitis was studied in gnotobiotic CD rats inoculated intranasally with the causal virus. Virus replication was detected sequentially in the nasopharynx, tracheobronchial tree, cervical lymph nodes, submaxillary and parotid salivary glands, exorbital gland, and Harderian gland. Acute rhinitis appeared within 2 days after inoculation, and salivary glands had lesions in 4 days. Early changes in salivary and exorbital glands were characterized by necrosis of ductal epithelium, which rapidly progressed to widespread acinar necrosis, marked inflammation, edema and total effacement of glandular architecture. Harderian glands also had massive necrosis of tubuloalveolar units. Repair in all glands was characterized by marked squamous metaplasia of tubuloalveolar units. Repair in all glands was characterized by marked squamous metaplasia of ducts. Neutralizing and complement-fixing antibodies were detected in 7 days, and there was a concomitant decrease in tissue-virus titers. There was no detectable evidence for hematogenous spread of virus or for retrograde infection by way of major salivary ducts.     

Carcinoma ex pleomorphic adenoma with sebaceous differentiation in the mandibular salivary gland of a dog

A carcinoma ex pleomorphic adenoma was diagnosed in the left mandibular salivary gland of an 8-year-old female spayed dog. The animal presented with a large nonpainful swelling in the left submandibular region. A computed tomography scan detected an irregularly enhancing soft tissue mass that was closely associated with the left external ear canal and extended to the left wing of the atlas. On surgical exploration, the mass was intimately associated with the left mandibular salivary gland. Both the mass and the adjacent gland were removed, and the diagnosis was determined by histopathology. The tumor was comprised of basaloid and low columnar epithelial cells, many glandular units formed by well-differentiated sebocytes, and multifocal regions of necrosis, mineralization, and hemorrhage. Salivary gland tumors with sebaceous differentiation are very rare in animals, with one previously reported case in a cat.     

Idiopathic salivary gland enlargement (sialadenosis) in dogs: a microscopic study

A histological, histochemical and morphometric study was performed on submandibular salivary glands from 13 dogs which had presented with a submandibular mass or swelling that proved to be a portion of non-inflammatory and non-neoplastic submandibular salivary gland. There were no consistent changes in lectin-binding histochemistry or immunohistochemical expression of various cell markers, and, in most cases, there was no measurable difference in acinar size in the affected gland. The possible explanation for the clinical salivary gland enlargement is therefore unclear.     

Experimental rabies in skunks: mechanisms of infection of the salivary glands.

Striped skunks (Mephitis mephitis) were inoculated into the right submandibular salivary gland with street rabies virus. They were killed at various times after inoculation and several tissues were examined by immunofluorescence and light microscopy. Right and left superior cervical, nodose and trigeminal ganglia, medulla oblongata and at least three regions of right and left submandibular salivary glands were examined by the fluorescent antibody technique. Intracerebral titrations of salivary gland suspensions were made in weanling white Swiss mice. Immunofluorescent material (inoculum) was detected in septa and connective tissue surrounding secretory units of the right submandibular gland immediately after inoculation, but otherwise antigen was not detected in either right or left submandibular glands without coincident antigen in the medulla oblongata. This occurred first on day 12 in areas of the gland remote from the inoculation site. Titers of virus were low at this time. Serum neutralizing antibodies occurred by day 7 in a few skunks. The time of development and distribution of antigen strongly suggest that, even after direct inoculation, neural networks are necessary for development of widespread infection of the salivary gland. The early occurrence of serum neutralizing antibodies in some of the skunks suggests that the immune response was activated by virus in the inoculum since immunofluorescence was not detected in any tissue at this time.     

Salivary gland disease in dogs and cats: 245 cases (1985-1988)

Diagnostic pathology records spanning 41 months (July 1985 through November 1988) were searched for diagnoses of salivary gland disease in dogs and cats. Review of 87,392 records from that period revealed 245 cases (0.3%) in which salivary gland tissue had been evaluated. During that period, salivary gland tissue was submitted to the laboratory almost twice as often from dogs (160 cases) as from cats (85 cases). On the basis of histologic examination, 89% of salivary gland submissions from small animal practices were allotted to 1 of 5 major categories: malignant neoplasms (30%; 74/245), sialadenitis (26%; 64/245), normal salivary gland (16%; 40/245), sialocele (9%; 21/245), and salivary gland infarction (8%; 20/245). The remaining 11% of submissions included various degenerative or fibrotic lesions, ductal ectasia, sialolithiasis, edema, benign neoplasia, and secondary salivary involvement with systemic or cervical lymphosarcoma or with fibrosarcoma in the head and neck.     

Cervical teratoma in a dog

A young adult boxer dog was examined for a painless swelling in the left cranial cervical area that was refractory to antibiotic therapy. Ultrasound examination revealed a hypoechoic mass abutting the rostrolateral aspect of the left mandibular salivary gland. The cystic mass was excised and was found to extend through the capsule of the salivary gland and appeared to be confluent with the glandular tissue at this point. Histopathological examination of the excised tissue demonstrated tissue from all 3 germinal layers. There was no indication of malignancy and the mass was diagnosed as a benign cervical teratoma. Hypotheses regarding the origin of teratomas in general are discussed and the origin of the teratoma in this case is suggested.     

Histology of salivary gland infarction in the dog.

Salivary gland infarction was found in two adult dogs. The main changes were ischaemic necrosis, capsular fibrosis and regenerative hyperplasia of surviving ductal epithelium. Necrosis of arterial tunica media and thrombosis were found only in the infarcted parts of the salivary glands. The lesions appeared to be confined to the salivary glands; no cause of the infarction was found.     

A case of spontaneous Zymbal’s gland carcinoma with lung metastasis in an aged Fischer 344 rat

Zymbal’s gland neoplasms are induced in rats through the administration of various carcinogens, but spontaneous neoplasia is rare. This report describes a spontaneous Zymbal’s gland carcinoma with lung metastasis found in an aged male Fischer 344 rat. Macroscopically, the dome-like tumor nodule, approximately 30 mm in diameter with ulceration, was located near the ear canal of the rat. No healthy tissue or structure of Zymbal’s gland was identified on the corresponding side, while the normal salivary glands and a lacrimal gland were observed. Histologically, a large part of the tumor mass was occupied by poorly differentiated neoplastic cells, the shapes of which were oval to polygonal or fusiform. Additionally, clusters of sebaceous-like foamy cells and squamous metaplasia with prominent keratinization were observed. Tumor cells were found to metastasize to the lung; these cells displayed histological similarities, including a sebaceous gland-like pattern, to those in the primary site. The tumor cells were immunohistochemically positive for cytokeratin AE1/AE3 or vimentin but negative for CD68, S100, α-smooth muscle actin, von Willebrand factor, and desmin. Our results indicate that the tumor was a poorly differentiated Zymbal’s gland carcinoma with lung metastasis.     

An unusual tumor of the nictitating membrane gland of dogs-- a case report]

A tumor of the third eyelid gland was diagnosed in a 13 year old female Chihuahua. Histopathology of the excised tissue revealed an apocrine adnexoma with squamous metaplasia. The literature regarding prolapse and tumors of the third eyelid gland was reviewed. No case with similar morphology to this tumor was described to our knowledge.     

Parotid salivary gland carcinoma in a geriatric horse

This case report describes a geriatric gelding with a 2 month history of fast‐growing masses within the parotid and submandibular regions. The horse was dyspnoeic on presentation and upper airway endoscopy revealed partial airway obstruction at the level of the pharynx, secondary to a space‐occupying mass. Cytological evaluation of multiple fine‐needle aspirates obtained from the masses were suggestive of salivary gland neoplasia, therefore the horse was subjected to humane euthanasia. A computed tomographical scan was obtained post mortem and revealed a large multi‐lobulated mass involving both guttural pouches, resulting in 80% occlusion of the naso‐ and oropharynx. Histopathology confirmed a parotid salivary gland carcinoma (papillary‐cystic type). Salivary gland tumours are extremely rare in horses, with only a few cases reported in the literature. Treatment of these malignancies proves to be challenging, requiring complete parotidectomy or surgical debulkment, in combination with adjunctive therapy.     

Lectin histochemistry on squamous metaplasia in different epithelial tumors of dogs.

Biotinylated lectins and avidin-biotin-peroxidase complex were used to study the correlation between cellular glycoconjugates' expression and squamous maturation in normal canine skin and in various epithelial neoplasms. Normal skin tissue was obtained from five, male, random-source dogs, 5 to 7 years old. The tumors tested, selected from the files of our Department, were fifteen squamous cell carcinomas from different tissue origin, five hepatoid perianal gland adenocarcinomas with squamous metaplasia, and fourteen solid mammary carcinomas with and without histologic evidence of squamous metaplasia. Except for mammary gland carcinomas, all tumors had been surgically excised from male dogs. Intermediate filament aggregation of twelve solid mammary gland carcinomas were studied electron microscopically. The basal and the lower spinous cells in normal skin and the less differentiated cells in squamous cell carcinomas stained moderately with Griffonia simplicifolia agglutinin-I. Spinous and granular cell layers stained strongly with Phytolacca americana mitogen and Arachis hypogaea agglutinin. Both lectins stained well-differentiated cells in squamous cell carcinomas. The electron microscopic study carried out in solid carcinomas of mammary glands revealed some relationship between the presence of intracytoplasmic tonofibrils and the binding of Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen to the tumors tested. Our results suggest that the glycosylation pattern occurring during normal keratinocyte differentiation is conserved in squamous cell carcinomas and that Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen may represent useful tools in distinguishing poorly differentiated squamous cell carcinomas from other poorly differentiated mammary epithelial tumors.     

Measurement of Carbonic Anhydrase Isozyme VI (CA-VI) in Bovine Sera,Saliva, Milk and Tissues

Concentrations of bovine carbonic anhydrase isozyme VI (CA-IV) in bovine serum, saliva, normal milk, colostrum, submandibular gland, liver, and mammary gland were determined. CA-VI was purified from bovine saliva and an antibody to CA-VI was generated. The concentrations of CA-VI in the saliva (7.8 ± 7.9 μg/ml), serum (2.1± 5.7 ng/ml), milk (7.9 ± 12.1 ng/ml), submandibular gland (284.7 μg/g protein), liver (921.0 ± 180.7 ng/g protein) and mammary gland (399.6 ± 191.2 ng/g protein) were determined by ELISA. No seasonal change in CA-VI levels was observed in normal milk. The concentration of CA-VI in colostrum (day 1 post partum) was 119 ng/ml and decreased rapidly by 1 month following birth. Mammary gland contained much smaller amounts than the submandibular gland. CA-VI mRNA was detected in the liver and mammary gland of cow by RT-PCR. The ELISA used in this study proved to be a precise and sensitive method for determining CA-VI concentrations in saliva, serum, milk and tissue specimens from cows. The ELISA may enable the study of changes in CA-VI associated with hereditary or metabolic disorders of the salivary gland, mammary gland and liver using small samples of saliva, serum or milk.     

Sebaceous carcinoma of the salivary gland in a cat

Sebaceous carcinoma of the submandibular salivary gland is described in a cat, tumour cells were characterized histologically by moderate amounts of pale eosinophilic or vacuolated cytoplasm. Tumour cells were stained with antibody to cytokeratins (CKs 5. 6, 8, 17 and 19) and with lectins Con A and wheat germ agglutinin (WGA); this occurs in many other types of salivary gland tumour and is a feature of normal salivary gland acinar cells.     

Aural carcinoma with chondroid metaplasia at metastatic sites in a dog

A case of aural carcinoma with chondroid metaplasia at metastatic foci in an 8-year-old male pug is described. Multiple metastases in both lungs and the right submandibular, parotid, retropharyngeal, cervical and prescapular lymph nodes were detected. Histologically, the skin of the right ear canal appeared to be diffusely infiltrated by cords and nests of neoplastic epithelial cells, showing multifocal contiguity with the overlying hyperplastic squamous epithelium. Most of the carcinomatous cells were arranged in a glandular-like pattern, with formation of lumens containing epithelial cells attached to the peripheral cell layer by elongated intercellular bridges. Scattered foci of keratinization with central accumulations of compact, laminated keratin were also observed, and histochemical stains failed to detect mucinous secretory material. Even though histological and histochemical findings were compatible with a diagnosis of acantholytic squamous cell carcinoma, CAM5.2 immunostaining was detectable in the majority, although not all, neoplastic cells, confirming a diagnosis of poorly differentiated ceruminous gland carcinoma. Pulmonary metastatic nodules revealed multifocal areas of cartilaginous metaplasia with apparent transition of carcinomatous cells to chondroid cells, showing nuclear atypia and focal cytokeratin immunostaining. Carcinomatous cells surrounding chondroid areas also revealed focal vimentin and S100 immunoreactivity. Histological evidence of transition between the two components, as well as the presence of intermediate cells displaying both epithelial and mesenchymal immunohistochemical features, strongly indicated a final diagnosis of carcinosarcoma, in which chondrosarcomatous elements were derived from carcinoma cells.     

TGF‐β1 attenuated branching morphogenesis of embryonic murine submandibular gland through Smad3 activation

Transforming growth factor‐β1 (TGF‐β1) plays several crucial regulatory roles in multiple physiological and pathological processes. The aim of this work was to investigate the role of TGF‐β1 in branching morphogenesis of salivary gland. We harvested and cultured submandibular salivary glands (SMGs) from murine embryos, which were then treated with exogenous TGF‐β1, or its neutralized antibody, Smad3 inhibitor, or Smad3 small interfering RNA (siRNA). Our results suggested that TGF‐β1 attenuated branching morphogenesis of embryonic murine SMG via Smad3 activation, thus playing a negative regulatory role in salivary gland development.     

Systemic granulomatous disease and sialometaplasia in a dog with Bartonella infection

Systemic granulomatous disease involving the spleen, heart, lymph nodes, omentum, liver, kidney, lung, mediastinum, and salivary glands developed in an 8-year-old Rottweiler. The dog also had sialometaplasia of both submandibular salivary glands. Bartonella henselae and B. vinsonii subsp. berkhoffii DNA was amplified from the salivary gland by polymerase chain reaction analysis. Bartonellae may be the cause of this systemic disease, but to the authors' knowledge, involvement of omentum, mediastinum, and salivary glands has not previously been reported in association with Bartonella infection. Bartonellae should be considered potential causes of sialometaplasia.     

Adenocarcinoma of the parotid salivary gland in a cow

A 6‐year‐old Girolando dairy cow was presented for evaluation of a large subcutaneous facial mass. Fine‐needle aspirates of the mass contained many neoplastic cells with high nuclear:cytoplasmic ratios arranged in sheets and loosely cohesive clusters with streaming erythrocytes and neutrophils in the background. Neoplastic cells were 13–25 μm in diameter and were round to cuboidal with variably distinct borders. Based on the signalment, anatomic location, and cytologic findings, differential diagnoses included salivary adenocarcinoma, squamous cell carcinoma, and mucoepidermoid carcinoma. The cow was euthanized and a necropsy was performed. The primary neoplasm arose from the left parotid salivary gland and meastatic tumor was found in the regional lymph nodes and lung. Histologically, the tumor was composed of anastomosing and irregular solid islets surrounded by scant stroma. Cells were negative for periodic acid‐Schiff (PAS), PAS‐diastase, and Alcian blue pH 2.5 stains, used to detect mucin. On immunohistochemical analysis, neoplastic luminal salivary gland cells expressed cytokeratin, but not S100, α‐smooth muscle actin, or vimentin. Peripheral cells of neoplastic islets were immunoreactive for p63. The final diagnosis was nonsecretory adenocarcinoma of the parotid salivary gland.     

Basosquamous carcinoma with systemic metastasis in a miniature Pinscher

Basosquamous carcinoma (BSCC) is a rare malignancy, primarily composed of basal cells with foci of squamous differentiation. It is considered to be histologically an intermediate type between basal cell carcinoma and squamous cell carcinoma, and is known to have aggressive behaviors. BSCC occurred in a 17-year-old female minipin with a history of surgical excision for a mammary tumor. The right upper hindlimb was severely enlarged to 8 x 5 cm. Cross-section showed a homogenous white to yellow-white mass compressing the surrounding muscular tissues. The tumor metastasized also to the lungs, heart, abdominal cavity, liver and salivary gland. Microscopically, basaloid cells were crowded into solid nests or lobules separated by well-developed fibrous tissues with occasional keratinizations. Since there was no skin lesions, the tumor is assumed to be originated from the formerly present tumor in mammary gland. To our literature review, this case is the first BSCC with systemic metastasis in a dog.