Dedifferentiated liposarcoma of the neck: CT findings

Head and Neck Sarcoma Tumor Board Survival Guide for Neuroradiologists: Imaging Findings, History, and Pathology

Sarcomas of the head and neck carry a poor prognosis as diagnosis is often delayed until a late stage of the disease. Accordingly, it is essential to be familiar with the clinical and imaging features of sarcomas to suggest an appropriate differential diagnosis for collaborating surgeons and pathologists. However, as there are only 1000-1500 cases in the United States annually, many radiologists lack experience with pertinent imaging findings of sarcoma and lack knowledge of both treatment and necessary follow-up. In this review, a brief discussion of WHO definitions and histopathology is included to decode information provided by pathologists. Finally, staging and treatments are illuminated to aid the radiologist with initial imaging staging and follow-up care. This review aims to increase the comprehensive knowledge of a neuroradiologist and further their value to the multidisciplinary tumor board.

From head and neck lipoma to liposarcoma: a wide spectrum of differential diagnoses and their therapeutic implications

PURPOSE OF REVIEW

To overview the array of differential diagnoses among lipomatous tumours of the head and neck with special focus on their evaluation, three-dimensional assessment, and their available treatments.

RECENT FINDINGS

The head and neck is an infrequent localization for lipomatous tumours, even though they represent the most common mesenchymal lesions. Lipoma, spindle cell/pleomorphic lipoma (SC/PL), atypical lipomatous tumour/well differentiated liposarcoma (ALT/WDLPS), de-differentiated liposarcoma (DDLPS), myxoid liposarcoma (MLPS), and pleomorphic liposarcoma (PLPS) are the most distinctive histotypes. Lipoma and SC/PL present alterations of chromosomes 12 and 13, ALT/WDLPS and DDLPS both show the Mouse Double Minute 2 amplification, whereas MLPS presents a CHOP gene fusion. Diagnosis of PLPS is purely morphological as there is no pathognomonic genetic alteration identified to date. Radiological assessment can be challenging for the presence of nonadipose components within the lesion. Surgery is the mainstay of treatment, even though achieving true radicality in terms of a large cuff of healthy tissue surrounding the tumour is not always realistic in the head and neck. Adjuvant radiation, eventually in combination with systemic chemotherapy, has been shown to improve overall survival in patients with positive margins, high-grade, deep, and more than 5 cm lesions. Further studies should be aimed at the evaluation of the role of hadron therapy, as well as targeted drugs against overexpressed proteins.

SUMMARY

Adequate differential diagnosis of the histotypes collected under the umbrella term of head and neck lipomatous tumours plays a fundamental role in treatment and follow-up of these lesions and requires specific expertise with referral to high-volume centres.

CERVICAL LIPOSARCOMA IN A 22 YEAR OLD MAN- AN UNCOMMON PRESENTATION

Liposarcomas are uncommon malignant growths, most of which occur in the retroperitoneum and lower extremities. Liposarcoma arising in the head and neck is an uncommon and a potentially life threatening malignancy. We present a 22 year-old male with a dedifferentiated cervical liposarcoma, who had local excision, with no recurrence at twenty months of follow-up. This patient has drawn our attention to the fact that although liposarcomas are rare in the neck and commonly occur in patients between 40 and 60 years, any neck swelling in the young with atypical features should raise suspicion as to the possibility of malignancy.

Dedifferentiated liposarcoma of the oral floor: A case study and literature review of 50 cases of head and neck neoplasm

Dedifferentiated liposarcoma (DDLS) has a relatively poor prognosis, however this neoplasm rarely occurs in the head and neck. To date, no definite protocol has been established for the diagnosis and treatment of head and neck DDLS. The present study reports the case of a 69-year-old male patient with DDLS of the oral floor. To the best of our knowledge, this is the first documented case of oral floor DDLS. In addition, this is the first reported case with the development of a second primary malignancy following the treatment of head and neck DDLS. A literature review of 50 cases of head and neck DDLS revealed that preoperative biopsy is not reliable for the diagnosis of these tumors and an accurate pathological diagnosis with total resection is preferred.

Fat: friend or foe? A review of fat-containing masses within the head and neck

Fat-containing lesions of the head and neck are commonly encountered in day-to-day practice. Our aim was to review the various imaging presentations of common and some uncommon fat-containing lesions within the head and neck with potential pitfalls and mimics. While most soft-tissue masses have a fairly similar density, the presence of fat in a mass lesion is easy to identify on both CT/MRI and can help narrow the differential. Case-based examples of lipomas, liposarcomas, lipoblastomas, dermoids, teratomas and other fatty lesions will be used to describe imaging features. While fat density can be helpful, differentiating benign from malignant fat-containing lesions can still pose a challenge. Lesions simulating pathology such as brown fat, fatty changes within organs and post-operative flaps are presented. Finally, examples of fatty lesions in atypical locations are shown to illustrate examples that should be kept in mind in any differential. The presence of fat in head and neck masses can aid radiologists in arriving at an accurate diagnosis. Knowledge of the imaging appearance of these fat-containing lesions and their mimics can help avoid unnecessary biopsy or surgery.

Dedifferentiated liposarcoma of the deep (paralaryngeal) soft tissue: lessons learnt from a case with a partly deceptively benign appearing dedifferentiated component

We present a case (female, 61 years of age) of dedifferentiated liposarcoma of the deep, cervical (paralaryngeal) soft tissue with a significant myxoid component and characteristic immunohistochemical (strong and diffuse expression of p16, mdm2 and cdk4 in both the well differentiated liposarcomatous and dedifferentiated components) and molecular genetic findings (MDM2-gene amplification on fluorescence in situ hybridization). The myxoid component which was present in the well differentiated liposarcomatous component gave the tumor atypical radiological features. The case presented initial diagnostic difficulties, mainly because of the bland histomorphological appearance of the limited biopsy material from the sampled non-lipogenic, dedifferentiated component. The dedifferentiated part of the tumor turned out to harbor significant heterogeneity with regards to cellularity, cytomorphology and proliferative activity.

Liposarcoma of the retropharyngeal space with rapidly worsening dyspnea: A case report and review of the literature

Liposarcomas represent a significant proportion of soft-tissue sarcomas. However, their occurrence in the head and neck is infrequent and they are exceedingly rare in the retropharyngeal space. The present study reports the case of a 58-year-old patient with retropharyngeal liposarcoma. Uniquely, the patient presented with rapidly worsening dyspnea. The diagnosis of liposarcoma was established following retropharyngeal tumor excision, although biopsies were performed twice. Adjuvant radiotherapy was refused by the patient. However, during the post-operative follow-up period, no sign of either local tumor recurrence or distant metastasis was observed. Previously reported cases were also reviewed to analyze the diagnosis, treatment and prognosis of this disease.