Lipomatosis of the canine parotid gland: case report with a literature review

Abstract

In this report, we describe a case of lipomatosis in the left parotid gland of an eight-year-old female Shetland sheepdog and review the relevant literature. Preoperative diagnosis of lipomatosis with Tru-Cut biopsy presented difficulties in this case. The postoperative diagnosis was based on the gross appearance of a non-infiltrative, circumscribed swollen mass in the parotid gland and the histological appearance of normal adipocytes that infiltrated into the parotid gland without involving surrounding structures. Additionally, flotation of the whole parotid gland in formalin solution together with well-maintained residual lobulation and a well-maintained configuration on the cut surface were identified as subsidiary characteristics of lipomatosis of the parotid gland. Lipomatosis of the parotid gland has been rarely reported in dogs and is a poorly understood condition.

A retrospective study of salivary gland diseases in 179 dogs (2010–2018)

“…3 These inconsistencies raise the suspicion that the morphologic features of salivary lipoma and lipomatosis may overlap and lead to confusion in terms of diagnosis. 17 In our case series, lipomatosis was originally diagnosed in 5 cases, with 2 other similar cases originally diagnosed as salivary lipoma. After our histologic reexamination, we reassigned the 2 lipomas to the lipomatosis group based on the widespread salivary infiltration by adipose tissue and absence of a tumor mass.…”

“…9 Salivary lipomatosis or lipomatous infiltration are rare lesions that need to be differentiated from infiltrative lipomas. 17 Although lipomatosis results in widespread infiltration and swelling of the salivary gland without a discrete tumor mass, infiltrative lipoma tends to form a tumor mass and infiltrate adjacent tissues. 17 However, lesions referred to as salivary lipomatosis forming a tumor mass have been described in dogs.…”

“…17 Although lipomatosis results in widespread infiltration and swelling of the salivary gland without a discrete tumor mass, infiltrative lipoma tends to form a tumor mass and infiltrate adjacent tissues. 17 However, lesions referred to as salivary lipomatosis forming a tumor mass have been described in dogs. 3 These inconsistencies raise the suspicion that the morphologic features of salivary lipoma and lipomatosis may overlap and lead to confusion in terms of diagnosis.…”

Sialolipoma of the sublingual salivary gland in a dog – first report

“…These tumors may be broadly categorized into typically adipocytic neoplasms (lipomas, fibrolipomas, angiolipomas, and liposarcomas and others) or lipoepithelial neoplasms containing different proportions of epithelial cell and fat components, such as pleomorphic adenomas and sialolipomas (Agaimy, 2013). Lipomatosis (i.e., lipomatous infiltration characterized by diffuse adipose infiltration leading to generalized salivary gland swelling) has also been described (Agaimy, 2013;Madarame et al, 2015). Lipomas, angiolipomas, lipomatosis and lipoadenomas are the major differential diagnoses in dogs, and are histologically distinguished by lack of a distinct fibrous capsule (Nagao et al, 2001).…”

Spinal epidural and synovial lipomatosis in a 3‐year‐old Eurasian dog receiving sustained steroid therapy

“…Trauma, chronic inflammation and short bowel syndrome were described as comorbidities of synovial lipomatosis in human cases (Malkoc & Korkmaz, 2018). In dogs, this condition has been anecdotally reported to affect the parotid salivary glands (Madarame et al., 2015; Pellegrino et al., 2019), pancreas (Muresan et al., 2019), subcutaneous tissues (Sechi et al., 2016), synovium (Orekhova & Schwarz, 2021) and epidural lumbosacral space (Meij et al., 1996). This report describes the first case of synovial and thoraco‐lumbar epidural lipomatosis in a young adult Eurasian dog.…”