Inflammatory Variant of Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma of the Buccal Mucosa: An Overview and Case Report with a 10-Year Follow-Up

Abstract

Liposarcomas of the oral cavity are rare. Those originating in the buccal mucosa cause challenging diagnostic and therapeutic issues since less than 40 cases of liposarcomas of the buccal mucosa and cheek have been reported in the worldwide literature. Herein, we present a case of atypical lipomatous tumor/well-differentiated liposarcoma affecting a 45-year-old female patient. Ultrasonography and magnetic resonance imaging confirmed a well-defined mass located in the right buccal mucosa, extending to the submucosal layers of the cheek. Histopathologically, a well-differentiated fatty neoplasm with presence of prominent stromal inflammatory cells was observed. Multifocally scattered bizarre hyperchromatic stromal cells, some of which multinucleated, were also observed. An immunohistochemical panel comprising vimentin, S-100, CD10, CD34, CD20, CD3, CD68, CD138, MDM2, Ki-67, and P53 was employed to better characterize the lesion. A local recurrence event occurred during a 10-year follow-up period. Surgical resection was performed during both episodes. We also provided an overview of demographic and clinicopathological characteristics, immunohistochemical features, imaging findings, and the differential diagnosis of liposarcoma of the oral cavity. Knowledge of the etiopathological and clinical aspects of this rare neoplasm is fundamental in order to rule out other conditions, including lipomatous lesions that affect the buccal mucosa.

Keywords: Atypical lipomatous tumor; Liposarcoma; Mouth mucosa; Oral cancer; Recurrence; Well differentiated liposarcoma.

Fig. 1

Initial clinical presentation. a Extraoral appearance showing asymmetry and swelling on the right side of the cheek. b Intraoral view exhibiting a firm, non-tender submucosal swelling with a color similar to that of the surrounding buccal mucosa. A slight focal telangiectasia in the region is worth noting

Fig. 2

Ultrasonography findings. A well-defined mass of echogenic appearance (grey line) located in the submucosal layers of the right buccal mucosa

Fig. 3

Magnetic resonance imaging (MRI) findings. a Coronal and b axial MRI showing a heterogeneous mass extending from the right buccal mucosa to the submucosal layers of the cheek in T1-weighted images

Fig. 4

Transoperative approach and gross appearance of the lesion. a Surgical removal of the mass located on the right buccal mucosa. b Gross appearance of the surgical specimen showing a yellowish red smooth tissue and measuring 3.0 × 3.0 × 3.0 cm. c Surgical specimen floating on the 10% buffered formalin surface

Fig. 5

Histopathologic features of an atypical lipomatous tumor/well-differentiated liposarcoma of the buccal mucosa. Tumor showing a well-differentiated fatty pattern (a) with the presence of notable stromal inflammatory cells and lymphoid follicles (b). The neoplastic cells showed pleomorphism, as well as hyperchromatic and bizarre (c), binucleated (d, e) or multinucleated (f) nuclei (hematoxylin and eosin [H&E]; original magnification × 10 (a, b) and × 40 (c–f)

Fig. 6

Immunohistochemical findings of an atypical lipomatous tumor/well-differentiated liposarcoma of the buccal mucosa. a Diffuse patterns of vimentin expression. b Vacuolated lipoblasts were positive for S-100. c B cells were positive for CD10. d CD34 was positive in the spindle cell membrane. e, f B cells and T cells were positive for CD20 and CD3, respectively. g CD68 and h CD138 positive macrophages. i Focal/nuclear wear and positivity for MDM2 in inflammatory cells. j Nuclear staining pattern for P53. k The Ki-67 labeling index was approximately 10% in the nuclei. (Immunohistochemistry [IHQ], original magnification × 40 a–j)