Lipomatosis of the minor salivary glands

Sialolipoma of the Floor of the Mouth with Immunohistological Analysis

Lipomas are relatively rare in the head and neck, and sialolipoma was described as an entity about 20 years ago as lipoma that entraps salivary gland tissue. Less than 10 cases have been described in the floor of the mouth not related to the major salivary glands. Here, we report a case of sialolipoma affecting the floor of the mouth in a 47-year-old patient and reviewed the clinical, histologic, and immunohistochemical characteristics of the lesion.

Supraglottic subepithelial benign mass lesions: Focus on clinical features of sialolipoma-like lesion

OBJECTIVES

Sialolipoma has been classified as a benign soft tissue lesion in the 2017 World Health Organization classification of head and neck tumors. To our knowledge, only one case of laryngeal sialolipoma has been reported in the English literature. We conducted a retrospective study to identify clinical characteristics of supraglottic sialolipoma-like lesion and differentiate it from other supraglottic subepithelial masses.

METHODS

Medical records of 16 patients with supraglottic subepithelial benign mass lesions who underwent histological evaluation between 2003 and 2019 were retrospectively analyzed. Sialolipoma-like lesion was defined as a local finding of a well-circumscribed gross mass with pathological presence of salivary gland-like parenchymal lobules with evenly interspersed adipose tissue.

RESULTS

Eight patients showed histological positivity for sialolipoma-like lesion, 3 for amyloidosis, 2 for hemangioma, and 1 each for cyst, lymphoid hyperplasia, and chondrometaplasia. Sialolipoma-like lesion tended to be predominant among men; those affected had a mean age of 52.8 (range, 39-74) years. By contrast, among patients with amyloidosis, the ratio of men to women was 1:2 (100% vs. 33%; p = 0.055). Fiberscopic examination of all patients with sialolipoma-like lesions identified well-circumscribed, yellowish masses, closely resembling local amyloidosis findings. Sialolipoma-like lesion was associated with a significantly higher body-mass index (BMI; 27.4 ± 2.8 kg/m²) than amyloidosis (21.6 ± 1.4 kg/m²; p = 0.014). The transoral approach was used for lesion resection in all patients with sialolipoma-like lesion. No patient experienced postoperative recurrence.

CONCLUSION

Laryngeal sialolipoma-like lesion might be more prevalent than was previously reported, and histological examination is important to differentiate it from amyloidosis. Supraglottic sialolipoma-like lesion must be differentially diagnosed in patients with high BMI presenting with well-circumscribed, yellowish supraglottic masses.

Sialolipoma of Parotid Gland a Rare Histological Presentation

Sialolipoma is a rare tumour found within both major and minor salivary glands, it is recently described as a variant of salivary gland lipoma. Sialolipoma was first described by Pusiol et al. (Indian J Pathol Microbiol 52(3):379-382, 2009). Sialolipoma is well circumscribed and contains mature adipose tissue admixed with benign salivary gland component. We report a case of 62 years old female who presented with the complaint of swelling in the right parotid region for 5 years duration. Apart from cosmetic reason she had no other complain. All specific investigations done were inconclusive and suggested a benign tumor. Histopathological examination after superficial parotidectomy suggested sialolipoma. As newly described tumor type, care should be taken to distinguish oncocytic sialolipoma from other salivary gland neoplasms such as simple lipoma, pleomorphic adenoma, or oncocytoma.

Nasal Fibrolipomatous Hamartoma, an Idiosyncratic Connective Tissue Malformation in an Infant

We describe a congenital mass in the nasopharynx of an infant presenting with dyspnea and feeding difficulties. Magnetic resonance imaging demonstrated 2 separate polypoid nasal cavity masses that were endoscopically resected. Histologically, both lesions were composed of mature adipose tissue with broad fibrous bands and several foci of brown fat. PLAG-1 and HMGA-2 were negative by immunostains. The best diagnosis was a fibrolipomatous hamartoma.

Lipomas of the oral cavity: clinical and histopathologic study of 41 cases in a Brazilian population

This study evaluated the clinical and histopathologic aspects of 41 cases of oral lipomas diagnosed in a Brazilian population. All records from patients diagnosed with oral lipoma between 1970 and 2008 were reviewed. Histological sections were evaluated by light microscopy. There was a predominance of females (2.4:1), with a peak incidence between the sixth and seventh decade. The buccal mucosa was the most affected site (53.7%), followed by the buccal sulcus (14.6%) and tongue (9.8%). Tumor size ranged from 0.5 to 10 cm and the mean reported duration was 48 months. Histologically, the following variants were identified: lipoma (41.5%), fibrolipoma (34.1%), spindle cell lipoma (9.8%), sialolipoma (9.8%), osteolipoma (2.4%), and chondrolipoma (2.4%). Most tumors were well delimited, irrespective of the variant. Lipomas are rare tumors of the oral cavity. The characterization of new variants, such as sialolipomas, and the identification of histological subtypes in already known variants, such as low-fat and fat-free spindle cell lipomas, highlight the importance for careful microscopic evaluation of these tumors, which might be combined with immunohistochemistry in some cases.

Sialolipoma: Report of two cases and review of the literature

Sialolipoma is a new variant of salivary gland lipoma first described in 2001. We present 2 cases of sialolipoma involving the soft palate and buccal mucosa of 2 female patients. A review of the English language literature revealed 16 cases of sialolipoma reported thus far. We have reviewed the clinicopathologic features of the literature cases and are adding the present 2 cases for a total of 18 cases. To the best of our knowledge, this is the first report of sialolipoma involving the buccal mucosa and the second case in the soft palate. The purpose of this publication is to increase awareness of this recently described variant of lipoma and to address the diagnostic challenges posed both clinically and histopathologically.

Island of salivary gland in adipose tissue: a report of three cases

Although uncommon, many variants of lipomatous lesions in or around salivary glands have been reported in the literature. We report a series of three such cases in the minor salivary gland region. The first case (oral floor) is a well-circumscribed lipocytic lesion admixed with glandular components (mucous acini, serous demilunes and ducts). The second case (alveolar mucosa) is a diffuse lipomatous proliferation with entrapped salivary glandular elements, muscles and blood vessels. The third case (palate) is similar to the first case but the gland is located at the periphery of the lesion. The purpose of the article was to report these three lesions and discuss in relation to other pertaining lipomatous lesions (sialolipoma, lipoadenoma, lipomatosis, lipometaplasia in pleomorphic adenoma and infiltrating lipoma).

Sialolipoma of the Floor of the Mouth: A Case Report

Intra-oral lipoma is a well-known entity, but lipomatous tumors including salivary gland tissue containing clustered or peripherally located ducts and acinar cells are uncommon. They are a newly recognized entity of salivary gland lipoma, designated sialolipoma. We describe a case of sialolipoma arising in the floor of the mouth presenting with apparently normal salivary gland tissue, as demonstrated by both histologic and immunohistochemical findings, in a 67-year-old female. Complete surgical removal of the tumor with preservation of the sublingual gland was implemented after a careful examination confirming that the lesion did not originate from the sublingual gland.

Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma

AIMS

We propose the designation 'sialolipoma' to establish and characterize a new category of benign lipomatous tumour occurring in salivary glands. Until now, these tumours have not been regarded as a distinct entity in the salivary glands.

METHODS AND RESULTS

We evaluated the clinicopathological and immunohistochemical features of seven sialolipomas among 2051 surgically resected primary salivary gland tumours deposited in our files. The seven patients with sialolipoma were five men and two women, aged 20-75 years (mean: 54.4 years). Five tumours had arisen in the parotid gland, one in the soft palate, and one in the hard palate. The tumours ranged from 10 to 60 mm (mean: 38 mm) in maximum diameter. Histologically, the tumours were characterized by a well circumscribed mass composed of glandular tissue and mature adipose elements. The adipose elements in the tumours arising in the parotid gland were more abundant than those arising in the minor salivary gland. The glandular components consisted of ductal, acinar, basal and myoepithelial cells, and closely resembled the cellular and structural compositions of normal salivary gland tissues. These findings were confirmed by immunohistochemical and ultrastructural studies. These components had no atypia, except for the presence of some minor variations, e.g. ductal ectasia with fibrosis and focal oncocytic metaplasia. In all cases, cell proliferative activity, as assessed by Ki67 (MIB1) immunostaining, was low. From these findings, it is likely that our cases were lipomas with secondary entrapment of the salivary gland elements. No recurrence was seen in all cases after superficial parotidectomy, or after surgical excision in the patients with palatal tumours.

CONCLUSIONS

We regard sialolipoma as a distinct variant of salivary gland lipoma that can occur in both the major and minor salivary glands. Superficial parotidectomy, or surgical resection in the case of palatal tumours, is an appropriate treatment for this benign tumour.