Well-differentiated liposarcoma of the floor of the mouth: Report of a rare case and review of the literature

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.

Massive low-grade myxoid liposarcoma of the floor of the mouth: A case report and review of literature

BACKGROUND

Oral liposarcoma is an extremely rare lesion that is often clinically misdiagnosed as a benign tumor due to its asymptomatic and indolent clinical course. Here, we report a case of massive low-grade myxoid liposarcoma (MLS) of the floor of the mouth.

CASE SUMMARY

A 71-year-old man presented with a huge mass in the left floor of the mouth. A biopsy was performed, and a diagnosis of a myxoid tumor suspicious for low-grade MLS or myxoma was made. Gadolinium-enhanced T1-weighted magnetic resonance imaging showed an intensely enhanced tumor lesion that occupies the left sublingual space and extends to the submandibular space. Submandibular dissection, tumor resection, and reconstruction with a radial forearm flap were performed. The surgical specimen exhibited histologically low-grade MLS. Fused in sarcoma (FUS, also known as TLS) and DNA damage-inducible transcript 3 (DDIT3, also known as CHOP) break-apart was not detected in the fluorescence in situ hybridization analysis. The tumor was completely encapsulated and did not require additional treatment. Furthermore, no recurrence was reported 40 mo after surgery.

CONCLUSION

We experienced an extremely rare, massive, low-grade MLS emerging from the floor of the mouth. Oftentimes, an MLS of the floor of the mouth lacks significant clinical findings and is often misdiagnosed. Although no FUS-DDIT3 fusion gene was detected, a low-grade MLS was ultimately diagnosed based on the histological findings.

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

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.

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.

Primary Myxoid Liposarcoma of the Greater Omentum in a Rhesus Macaque (Macaca mulatta)

We here report a spontaneous case of primary myxoid liposarcoma of the greater omentum with subsequent transperitoneal recurrence. The primary mass was incidentally found during an exploratory laparotomy for a presumed diagnosis of trichobezoar or phytobezoar and was removed surgically. Histopathologic examination of the mass revealed the presence of a myxoid liposarcoma. Eleven months later, recurrence with severe transperitoneal sarcomatosis of the myxoid liposarcoma was noted and confirmed by necropsy and histopathology. A review of the literature revealed that liposarcoma in NHP conforms to the behavior and prognosis of this neoplasm in humans.

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.

Liposarcoma of the glottis: A report of an unusual diagnosis in an unusual location

Liposarcoma of the larynx is a rare entity, typically well differentiated with a good prognosis. We present a patient who presented to ENT clinic with a 3-month history of hoarseness. Contrast-enhanced computed tomography of the neck demonstrated a 2.5-cm mass of the true vocal cord, which biopsy demonstrated to be dedifferentiated liposarcoma of the larynx. The patient went on to total laryngectomy with planned adjuvant radiation therapy. The presentation and imaging findings of laryngeal liposarcoma are nonspecific, but this neoplasm should be considered in the differential of masses in the head and neck.

Primary liposarcoma of the diaphragm: a rare intra-abdominal mass

Primary malignant tumors of the diaphragm are rare, and primary liposarcoma of the diaphragm is extremely rare. The role of imaging is description of the anatomic relationships of the tumor as well as a suggestion of histologic diagnosis based on the presence of fatty and/or nonfatty components.