Myxoid/round cell liposarcoma of the supraclavicular fossa.
Metastases from the tracheobronchial tree and the genitourinary and gastrointestinal systems are the most common malignant lesions of the supraclavicular fossa. Liposarcomas in this region, as primary tumors, are rarely encountered. In this article, we report a case of myxoid liposarcoma of the supraclavicular fossa with a fulminant course.
Metastases from the tracheobronchial tree and the genitourinary and gastrointestinal systems are the most frequently occurring malignant lesions of the supraclavicular fossa. The most common primary malignancy in this region is sarcoma, which accounts for less than 1% of head and neck malignancies. (1) Only 2% of these are liposarcomas. (2,3) The neck is the most common site (19 to 38%) for head and neck liposarcomas, followed by the upper aerodigestive tract and face. (1-4)
Pathologically, liposarcoma can be separated into the following 5 major morphologic subtypes: welldifferentiated, myxoid, round cell, &differentiated, and pleomorphic. (5) The myxoid variant, which is characterized by the chromosomal translocation t(12;16) (q13;p11), is a lobulated soft-tissue tumor composed of slender, hyperchromatic spindle cells and signet-ringlipoblasts, a plexiform vascular pattern, and a myxoid matrix. We report a case involving a patient with a supraclavicular fossa liposarcoma that was treated by radical neck dis-section.
A 45-year-old woman presented with a 6-month history of an enlarging, painless, right supraclavicular mass and progressive weakness of her right arm. Her medical history was unremarkable, and she denied using tobacco or alcohol. Physical examination revealed an 8 x 6-cm, firm mass filling the right supraclavicular fossa and extending into the upper posterior cervical triangle. The abduction and rotation of the shoulder and flexion of the forearm were totally lost. The rest of the physical examination was unremarkable.
Contrast-enhanced computed tomography (CT) revealed an 8 x 6 x 5-cm mass in the lower portion of the right neck. The mass was heterogeneous with necrotic areas and was well circumscribed at the anterior and superior portions. Invasion into the transverse processes of the cervical vertebrae was present (figure 1). Magnetic resonance imaging demonstrated a lobulated, heterogeneous mass that was predominantly hyperintense in T1- and T2-weighted sequences. Invasion into the soft tissues in the supraclavicular fossa was noted.
Following fine-needle aspiration biopsy, which demonstrated malignancy, a radical neck dissection was performed. The tumor was found to be well circumscribed in the anterior and superior portions but had invaded the transverse processes of the cervical spine and soft tissues of the neck in the supraclavicular region. Histopathology with H&E stain showed lipoblasts with vacuolated cytoplasm and hyperchromatic, large, round to oval nuclei and atypical pleomorphic mesenchymal cells in a prominent myxoid stroma and scattered adipocytes. This appearance was compatible with a diagnosis of myxoid/round cell liposarcoina (figure 2). The patient was referred for radiation therapy, but she refused further therapy and died 6 months postoperatively from locally advanced disease.
The most common malignant lesions of the supraclavicular fossa are metastases from the tracheobronchial tree and the genitourinary and gastrointestinal systems. The most common primary malignancy in this region, although rare, is sarcoma. Although liposarcoma is one of the most common malignant soft-tissue tumors in adults, only 4% of liposarcomas are located in the head and neck. (1) Similarly, sarcomas comprise less than 1% of head and neck malignancies; of these, 2% are liposarcomas. (2,3) Liposarcomas of the head and neck are seen in all age groups, with the majority occurring in the fourth and fifth decades; a male preponderance is reported in most of the series. (1,4)
[FIGURE 1 OMITTED]
Enzinger and Weiss (5) have distinguished 5 pathologic variants of liposarcomas: (1) well-differentiated, (2) myxoid, (3) round cell, (4) dedifferentiated, and (5) pleomorphic. Although this classification received wide acceptance, a newer classification, reinforced by cytogenetic and molecular evidence, has been proposed, consisting of myxoid/round cell, well-differentiated/ dedifferentiated, and pleomorphic variants?
The well-differentiated variant accounts for approximately 40% of liposarcomas. (1,6) This variant displays indolent behavior and recurs locally, especially when surgical excision is incomplete, but its metastasis is decidedly rare. Dedifferentiated tumors arise in previously existing well-differentiated tumors. These two variants, occupying the edges of the histologic spectrum, show the same chromosomal abnormality--a supernumerary ring chromosome and/or a giant chromosome composed of the q13 to q15 regions of chromosome 12. (7) The &differentiated variant is considered to be a high-grade tumor, but its behavior is not as aggressive as the pleomorphic variant.
[FIGURE 2 OMITTED]
Pleomorphic liposarcomas represent only 5% of all liposarcomas and are characterized by a disordered growth pattern and cellular pleomorphism with prominent mitotic activity. (7)
Myxoid liposarcomas are as common as the welldifferentiated type; they are composed of proliferating lipoblasts at varying stages of differentiation, signet ring cells, a plexiform capillary pattern, and a myxoid matrix with nonsulfated glycosaminoglycans. (5) Macroscopically, these tumors display a lobular pattern and a fibrous pseudocapsule surrounding the lobules.
Approximately 40% of myxoid liposarcomas show more than 5% round cell differentiation, and both myxoid and round variants are associated with unique translation t(12;16)(q13;q11) that results in the fusion of two genes known as TLS and CHOP] The round cell variant is actually a poorly differentiated variant of myxoid liposarcoma. Pure round cell tumors are rare.
Although these pathologic classifications provide some practical benefits, different types may exist within the same tumor. Our case is an example of this: Myxoid and round cells were the dominating cell types, occurring at equal rates, and pleomorphic cells comprised only one-fifth of the tumor mass.
The single most important factor in terms of prognosis is the histologic type of tumor. (1) Myxoid tumors are considered to be locally invasive lesions that rarely metastasize and are associated with an 85% 5-year survival rate? However, 5-year survival rates for patients with pleomorphic and round cell tumors are only 21 and 18%, respectively. (5) In mixed lesions with multiple cellular elements, the most aggressive component determines the prognosis. The prognosis of myxoid tumors gets significantly worse as the round cell ratio within the tumor increases. (7)
The mainstay of treatment for liposarcoma is complete excision with wide surgical margins, as in other soft-tissue malignancies. McCulloch et al report an 80% recurrence rate with incomplete removal that decreases to 17% with comprehensive resection. (4) However, crucial structures of the head and neck make complete resection challenging, and sometimes even impossible. In such cases, the potential benefits of postoperative radiation therapy must be considered. In earlier studies, 5-year survival improvements were reported with postoperative radiation therapy, (8) but more recent studies have tailed to verify these results) Adjuvant radiotherapy for the head and neck sarcomas significantly increases local control and local recurrence rates, but the overall survival remains the same. (3)
Although liposarcoma of the neck is a rare entity, it is important for the head and neck surgeon to be aware of its natural behavior and management. Comprehensive surgery is usually adequate for the management of myxoid and well-differentiated liposarcomas. In highgrade tumors with aggressive behavior, complete excision, which cannot be replaced by adjuvant therapies, is of paramount importance. Nevertheless, potential benefits of radiation therapy for local control should be appreciated.
(1.) Davis EC, Ballo MT, Luna MA, et al. Liposarcoma of the head and neck: The University of Texas M.D. Anderson Cancer Center experience. Head Neck 2009;31 (l):28-36.
(2.) de Vreeze RS, de long D, Koops W, et al. Oncogenesis and classification of mixed-type liposarcoma: A radiological, histopathological and molecular biological analysis. Int J Cancer 2011; 128(4):778-86.
(3.) Eeles RA, Fisher C, A'Hern RP, et al. Head and neck sarcomas: Prognostic factors and implications for treatment. Br J Cancer 1993; 68(1):201-7.
(4.) McCulloch TM, Makielski KH, McNutt MA. Head and neck lip sarcoma. A histopathologic reevaluation of reported cases. Arch Otolaryngol Head Neck Surg 1992;118(10):1045 9.
(5.) Enzinger FM, Weiss SM. Liposarcoma. In: Enzinger FM, Weiss SM (eds). Soft Tissue Tumors. 3rd ed. St. Louis: Mosby; 1995:431-66.
(6.) Dei Tos AP. Liposarcoma: New entities and evolving concepts. Ann Diagn Pathol 2000;4(4):252-66.
(7.) Newlands SD, Divi V, Stewart CM. Mixed myxoid/round cell liposarcoma of the scalp. Am J Otolaryngol 2003;24(2):121-7.
(8.) Pack GT, Pierson JC. Liposarcoma: A study of 105 cases. Surgery 1954;36(4):687-712.
Cagatay Oysu, MD; Celil Uslu, MD; Barls Naiboglu, MD; Evren Ay Ogredik, MD
From the Department of Otolaryngology; Umraniye Research aim Education Hospital (Dr. Oysu); Central Hospital (Dr. Uslu); aim the Department of Otolaryngology, Haydarpasa Numune Research and Education Hospital (Dr. Naiboglu and Dr. Ogredik), Istanbul, Turkey,
Corresponding Author: Dr. Cagatay Oysu, MD, Umraniye Egitim ve Arastirma Hastanesi Elmahkent mah. Adem Yavuz cd. No:l, Istanbul, Turkey. Email: firstname.lastname@example.org
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|Title Annotation:||ORIGINAL ARTICLE|
|Author:||Oysu, Cagatay; Uslu, Celil; Naiboglu, Baris; Ogredik, Evren Ay|
|Publication:||Ear, Nose and Throat Journal|
|Article Type:||Case study|
|Date:||Feb 1, 2012|
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