Atypical lipomatous tumors of the tongue: report of six cases

Well-differentiated liposarcoma of tongue: A case report

Key Clinical Message

It is important to consider WDLS as a potential cause of tongue lesions and include it in the list of differential diagnoses. When performing surgical intervention, it is crucial to remove enough tissue around the lesion, and regular follow-up is necessary due to the high risk of recurrence, despite its rarity, when margins are positive.

Abstract

Liposarcoma (LS) is the most common soft tissue sarcomas (STSs) that arise from embryonic mesenchymal tissue. Though these sarcomas commonly arise at retroperitoneal locations and extremities, the appearance of these tumors in the head and neck region is rare, with the tongue as a preferred site. As per WHO 2020, LS is classified into four subtypes based on morphology, namely, Well-differentiated liposarcoma (WDLS), Dedifferentiated liposarcoma (DDLS), Myxoid liposarcoma (MLS), and Pleomorphic liposarcoma (PLS). WLS is the most common variant among all. Here, we had a case of 55 years old male with the complaint of swelling in the left lateral border of the tongue with the preliminary diagnosis of pleomorphic adenoma. The patient underwent a left partial glossectomy with adequate margins. Further evaluation of the lesion revealed a clear cell tumor that was ultimately confirmed as liposarcoma on immunohistochemistry that showed tumor cells positive for S100, CDK4, and MDM2 with 2% Ki-67. Postsurgical status of the patient was evaluated by F18 FDG PET CTscan, which was normal. Currently, the patient is under regular follow-up.

Intraoral lipoma with degenerative changes mimicking atypical lipomatous tumor: an immunohistochemical study

Lipomas are mesenchymal neoplasms relatively uncommon in the oral cavity. Lipomas can exhibit histopathological features mimicking atypical lipomatous tumors (ALT) or dysplastic lipoma (DL) in the presence of degenerative changes. Relevantly, immunohistochemistry assists in the correct diagnosis. Herein, we present the case of a 54-year-old male with a sessile nodule located on the dorsum of the tongue. The histopathological analysis showed a diffuse, non-circumscribed adipocytic proliferation constituted by cells of variable size containing cytoplasmic vacuoles and displaced nuclei, some resembling lipoblasts supported by fibrous connective tissue stroma. By immunohistochemistry, tumor cells were positive for vimentin, S100, FASN, CD10, and p16. Rb expression was intact. Moreover, CD34, p53, MDM2, and CDK4 were negative. After 2-year of follow-up, no alteration or recurrence was observed. In conclusion, MDM2, CDK4, p53, and Rb immunomarkers can be used reliably to differentiate benign lipoma with degenerative changes from ALT and DL.

Liposarcoma in children and young adults: a clinicopathologic and molecular study of 23 cases in one of the largest institutions of China

The incidence of pediatric liposarcoma is rare and most published cases lack systematic genetic analyses. We present clinicopathologic and genetic features of 23 liposarcomas aged <22 years. The study cohort comprised 10 males and 13 females (M:F=1:1.3) aged 11-21 years (median 17 years). The tumors predominantly occurred at the extremities (16/23; 69.6%), followed by the head/neck (2/23; 8.7%), chest (2/23; 8.7%), waist (2/23, 8.7%), and retroperitoneum (1/23; 4.3%). The tumor subtypes were sixteen myxoid liposarcoma (ML), one well-differentiated liposarcoma (WDL), two dedifferentiated liposarcoma (DDL), one pleomorphic liposarcoma (PL), and three myxoid pleomorphic liposarcoma (MPL) cases. Fluorescence in situ hybridization analysis identified MDM2/CDK4 amplification in all WDL/DDL cases (3/3; 100%) and DDIT3 rearrangement in all ML cases (13/13; 100%). Whole-exome sequencing indicated that one PL case and one MPL case exhibited RB1 loss. The two tested MPL cases had TP53 mutation and one of them harbored a TP53 germline mutation. Follow-up information was available for 20 patients (20/23; 87.0%) with a median follow-up duration of 42.5 months (range, 13-120 months). Three patients exhibited tumor progression (3/20;15.0%). Seventeen patients (17/20; 85.0%) survived with no evidence of disease. One MPL case (1/20; 5.0%) died of the disease. In conclusion, despite some overlaps, the occurrence, distribution of subtype, and prognosis of liposarcoma are overall different in children and adults. Most MLs and ALT/WDL/DDLs showed similar genetic aberrations with adult counterparts. Molecular features of MPL overlapped with those of conventional PL. The genetic characteristics including Tp53 status of MPL need further investigation.

Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma Arising from the Tongue: case report

<p>Liposarcomas are common mesenchymal malignant tumors arising from adipose tissue. Although liposarcomas are the most frequent type of soft tissue sarcomas, accounting for approximately 20% of all soft tissue sarcomas, they are rare in the head and neck, particularly in the oral cavity. Oral liposarcomas have been reported to occur mainly on the buccal mucosa, with other sites including the floor of the mouth, tongue, palate, and mandible. This report describes a 76-year-old male patient with an atypical lipomatous tumor/well-differentiated liposarcoma of the tongue that underwent surgical excision. This report also reviews published data on these rare tumors.

Well-Differentiated/Dedifferentiated Liposarcoma Arising in the Upper Aerodigestive Tract: 8 Cases Mimicking Non-adipocytic Lesions

Well-differentiated (WDL) and dedifferentiated liposarcomas (DL) of the pharynx, larynx and oral cavity are rare, often mimicking benign lipomatous neoplasms or non-lipogenic mesenchymal tumors. Cases of WDL/DL arising in the upper aerodigestive tract, exclusive of the cervical esophagus, were reviewed. Morphologic features, ancillary studies, including fluorescence in situ hybridization (FISH) studies for CPM/MDM2, and clinical data was catalogued. Eight WDL/DL (4 WDL, 4 DL); were identified in patients ranging from 32 to 77 years (median 52.5 years; 6 males, 2 females) with sites of origin including hypopharynx (5 cases), larynx (2 cases) and oral cavity (1 case). Six of the 8 cases were received for expert consultation, and the remaining 2 cases were initially misdiagnosed as benign lymphangiomatous or fibroepithelial polyps. Morphologically, 4 tumors had areas mimicking various non-lipomatous soft tissue tumors including nodular fasciitis, mammary-type myofibroblastoma, low-grade myofibroblastic sarcoma and undifferentiated pleomorphic sarcoma, 2 cases simulated benign hypopharyngeal polyps, and 1 lesion was notable for a dense lymphoplasmacytic infiltrate suggestive of hematolymphoid neoplasm or IgG4-related sclerosing disease. FISH showed amplification of CPM/MDM2 (8/8 cases). All cases (4/4) with longer than 1-year of follow-up recurred (45-118 months) with 1 tumor showing progression to DL. WDL/DL presenting in the upper aerodigestive tract are rare and diagnostically challenging. Awareness of the morphologic spectrum of WDL/DL coupled with appropriate use of MDM2 FISH is essential for accurate classification and management, as these tumors appear to have a high risk for local recurrence and eventual dedifferentiation in these anatomical locations.

Liposarcoma of oral cavity: Systematic review of cases reported to date and analysis of prognostic factors

The aim of this study was to integrate the available data published on Liposarcomas (LPSs) of the oral cavity into an analysis of its clinical features, treatment modalities, and prognostic factors. An electronic search was undertaken in January 2019. The eligibility criteria included publications that had enough clinical and histological information to confirm the diagnosis. Forty-five publications (104 LPSs) were included. The lesion was more prevalent in males from the fifth to seventh decades of life. Treatment (P = .03) and distant metastasis (P = .0001) were independently associated with survival. A lower possibility of recurrence was statistically associated with age (younger patients) (P = .03), tumor size (smaller than 2.8 cm) (P = .001), and treatment (radical surgery) (P = .04). LPS presents a good survival for patients after 5 years of follow-up (66.4%). Patients who were treated with conservative surgery and presented with distant metastasis showed poor prognosis.

Oral liposarcoma in elderly: Case report and literature analysis

RATIONALE

Oral liposarcoma is an extremely rare lesion that is often clinically misdiagnosed as a benign lesion because of its asymptomatic and indolent clinical course. we report a case of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) of buccal mucosa, provisionally diagnosed as lipoma.

PATIENT CONCERNS

A 97-year-old female was referred to dentistry and oral surgery department with an asymptomatic mass on the right buccal mucosa which had been present for an unknown period of time.

DIAGNOSIS

Magnetic resonance imaging demonstrated a well-circumscribed lesion at the right buccal mucosa, and a lipoma was suspected.

INTERVENTIONS

Surgical removal was performed, and a diagnosis of ALT/WDL was made. She and her family refused additional treatment due to her age.

OUTCOMES

At the 10 months follow-up, the patient remained free of disease.

LESSONS

The indolent clinical course and small size of oral liposarcoma can lead to provisional clinical diagnosis of benign lesion.

Lipomas of the Oral Cavity: Utility of MDM2 and CDK4 in Avoiding Overdiagnosis as Atypical Lipomatous Tumor

Traumatized lipomas with degenerative change may demonstrate histopathologic features that mimic atypical lipomatous tumor (ALT). Previously reported series of ALT involving the oral cavity preceded routine use of MDM2 and CDK4 immunohistochemistry. Our aim is to evaluate MDM2 and CDK4 immunohistochemical expression in adipocytic tumors arising in this site, in conjunction with the histiocytic marker PU.1, to determine whether MDM2 and CDK4 impacts classification. 17 cases originally diagnosed as ALT were retrieved and immunohistochemical studies for MDM2, CDK4 and PU.1 were performed. FISH analysis for MDM2 amplification was performed in select cases. For this study group, the male:female ratio was 9:8 and the median age was 62 (range 41-88). All 17 cases presented as well- or predominantly well-circumscribed proliferations of variably sized, mature adipocytes exhibiting uni- or multi-vacuolation with occasional scalloped nuclei and mild nuclear atypia. Variable amounts of fibrous stroma with focal myxoid change and bland spindle cells were identified in 14/17 cases. Lipoblasts or atypical hyperchromatic stromal cells were not identified in any cases. 14 of 17 cases were negative for MDM2 and CDK4 in tumor cells and 11 of these 14 showed weak nuclear positivity for MDM2 in histiocytes. 3 of 17 cases showed weak, multifocal immunohistochemical expression of MDM2 and CDK4. PU.1 highlighted histiocytes in all 17 cases. FISH analysis for MDM2 amplification was negative in all 3 cases with weak MDM2/CDK4 expression. All cases were reclassified as lipoma with degenerative changes. ALT, in all likelihood, is less common than previously thought in this anatomic location and best diagnosed with ancillary studies. MDM2 expression in histiocytes is best interpreted in conjunction with CDK4 immunohistochemistry and confirmatory FISH for MDM2 amplification.

Pleomorphic lipoma of the tongue as potential mimic of liposarcoma

We herein report a rare case of pleomorphic lipoma of the tongue with a review of world literature. A 44-year-old woman presented with a nodule of the tongue that had been present for over three years. Clinical examination revealed a yellowish sub-mucosal lesion, measuring 3 cm in maximum diameter, protruding from lingual surface. A first biopsy showed a lipomatous tumour composed of mature adipocytes intermingled with myxoid areas composed of spindle uniform in size and shape and multinucleated floret-like giant cells. Spindle and giant cells were positive for CD34. A diagnosis of pleomorphic lipoma was made. In view of the benign nature of this mass, it was de-bulked rather than completely excised in order to preserve swallowing function.

Atypical lipomatous tumor of the cheek - a case report

Liposarcoma is the most common soft tissue malignant tumor. It mostly arises in the subcutaneous tissue of shoulders, limbs and neck, and retroperitoneal space, but head occurrence is very rare. Atypical lipomatous tumor (ALT) is a well-differentiated liposarcoma (WDLPS) and constitutes 40-45% of all liposarcoma cases. A case of 57-year-old woman with a tumor of the left cheek, causing a discreet face asymmetry is presented. The tumor was soft and caused no tenderness. The patient reported no previous injury of the region. Fine-needle aspiration biopsy (FNAB) revealed atypical cells suspected of liposarcoma. MR examination showed fascicles of adipose tissue, which made the left cheek prominent. The patient was operated under general anaesthesia. Adipose tissue of the left cheek was removed. Postoperative course was uneventful. The final histopathological diagnosis - was atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS). The patient remains under laryngological care. No recurrence of the disease has been observed during the 5 years follow-up.

Well-differentiated liposarcoma/atypical lipomatous tumor of the oral cavity: report of three cases and review of the literature

Atypical Lipomatous Tumor/Well Differentiated Liposarcoma (ALT/WDLS) is a soft tissue sarcoma of intermediate malignant behavior, most frequently affecting the retroperitoneum and lower extremities. Oral liposarcomas are very rare neoplasms, the most common histological subtype being ALT/WDLS. In this study, three additional cases of ALT/WDLS located on the tongue (2 cases) and the lower lip (1 case), respectively, are described. Analysis of the salient clinicopathologic features of 63 oral ALT/WDLS cases previously reported in the English language literature, as well as of the 3 cases presented in this study, indicates that the indolent biologic behavior of this tumor justifies its designation as a locally spreading malignant neoplasm, affording a rather conservative surgical approach.