Carcinoma ex Pleomorphic Adenoma with Sebaceous Differentiation in the Mandibular Salivary Gland of a Dog

Abstract

Abstract. 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.Key words: Carcinoma; dogs; salivary gland; tumor.An 8-year-old female spayed Basset Hound was presented to the University of Tennessee Veterinary Teaching Hospital because of a mass located in the left submandibular area. The mass was first noticed by the owners 2-3 months prior to presentation and was gradually increasing in size. The dog was otherwise healthy and exhibited no clinical signs associated with the mass. At presentation, the mass was subcutaneous, fixed, and firm on palpation. Fine needle aspirate of the mass revealed many streaming erythrocytes and nucleated cells, suggesting a mucinous background. The heterogeneous cell population consisted of a few large aggregates of well-differentiated salivary secretory epithelial cells and several large clusters of uniform, basophilic cells exhibiting a high nuclear-to-cytoplasmic ratio. The aspirate was considered to be of salivary gland origin; differentials for the mass included basal cell tumor or a well-differentiated ductular tumor.A computed tomography (CT) scan showed a focal, well-circumscribed, heterogenous-density mass measuring approximately 44 (dorsoventral dimension) 3 35 (mediolateral dimension) 3 48 (rostrocaudal dimension) mm arising within the left mandibular salivary gland (Fig. 1). The mass was expansive within the gland, effacing the adjacent gland parenchyma. Postcontrast images revealed nonuniform enhancement of the mass with normal strong uniform enhancement of the adjacent compressed glandular tissue. There was mild enlargement of one of the adjacent submandibular lymph nodes. Imaging diagnosis was of a discrete mass arising within the left mandibular salivary gland with mild associated lymphadenomegaly. Primary consideration was given to a neoplastic process.Surgical excision of the mass and an enlarged left submandibular lymph node was performed. Grossly, the mass was intimately associated with the left mandibular salivary gland. The salivary gland itself, however, was compressed by the mass to the periphery and did not appear to be involved.Four sections of the mass with adjacent salivary gland and two sections of th...

MR Anatomy of Salivary Glands in the Dog

“…Although MRI is becoming increasingly more essential in modern veterinary diagnostic investigations, literature review revealed just a single application in an experimental study for evaluating the function of a pilocarpine‐stimulated mandibular gland (Tsuchimochi et al., 1991). When considering sectional imaging techniques, only computed tomography was used to diagnose salivary gland neoplasia (Carberry et al., 1987; Brown et al., 1997; Sozmen et al., 2003; Shimoyama et al., 2006; Smrkovski et al., 2006; Faustino and Dias Pereira, 2007) and sialoceles or silaoliths (Hunt et al., 1997; Smrkovski et al., 2006; Bartoe et al., 2007; Trumpatori et al., 2007; McGill et al., 2009), even though MRI has superior soft‐tissue contrast (Klumpp et al., 2009).…”

Apocrine Sweat Gland Ductal Adenoma with Sebaceous Differentiation in a Dog

“…According to the World Health Organization classification of epithelial and melanocytic tumors of the skin of domestic animals, benign tumors of the apocrine sweat gland are classified as apocrine adenomas, complex and mixed apocrine adenomas, or apocrine ductal adenomas [2]. In dogs, sebaceous differentiation has been described in four cases of mammary gland tumors: two complex adenomas [3,4] and two carcinomas [5,6] and a case of salivary gland tumor [7], whereas one has not been previously described in apocrine sweat glands. The present report describes a case of apocrine sweat gland ductal adenoma with sebaceous differentiation occurring in the buccal skin of Border Collie.…”

Magnetresonanztomographische Anatomie der Speicheldrüsen der Katze

“…Beim Hund finden sich in der Literatur Fallberichte zum Einsatz von CT und MRT zur Diagnostik von Speicheldrüsenerkrankungen. So diente die CT zur Diagnostik von Entzündungen (6), Mukozelen (1,22), Neoplasien (30) und der Identifikation eines Fremdkörpers im Ductus parotideus (15). Mit der MRT wurden Sialadenitiden (6), die Invasivität orbitaler Erkrankungen (7) und das Potenzial zur Differenzierung von Veränderungen der Glandula (Gl.)…”