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Case Report Sarcoma
Monophasic Synovial Sarcoma of the
Infratemporal Fossa—Case Report and
Review of the Literature
Ignacio Mendoza, 1 Ilson Sepúlveda, 2 and Geraldine Ayres 3
1. ENT-Head and Neck Surgery Service, General Hospital of Concepcion, University of Concepcion School of Medicine, Concepcion, Chile; 2.
Radiology Department; ENT-Head and Neck Surgery Service, General Hospital of Concepcion, Concepcion, Chile; 3. Pathology Department, General
Hospital of Concepción, University of Concepcion School of Medicine, Concepcion, Chile
S ynovial sarcoma (SS) represents about 10% of all soft tissue sarcomas. It is believed that its origin would be found in cells that are
related neither to ultrastructural nor to histological features of the synovial tissue. Head and neck is very rarely affected, with the lower
extremities being most frequent. Complete resection with or without radiotherapy and chemotherapy is currently considered the best
available therapy. This time we present the case of a patient with SS located in the infratemporal fossa, its diagnosis, treatment and evolution.
According to our knowledge it is the first reported case in South America.
Keywords Synovial sarcoma, head, neck, infratemporal fossa,
computed tomography, magnetic resonance
Disclosure: Ignacio Mendoza, Ilson Sepúlveda,
and Geraldine Ayres have nothing to disclose
in relation to this article. No funding was
received in the publication of this article.
Compliance with Ethics Guidelines: All procedures
were followed in accordance with the responsible
committee on human experimentation and with
the Helsinki Declaration of 1975 and subsequent
revisions, and informed consent was received
from the patient involved in this case study.
Authorship: All named authors meet the International
Committee of Medical Journal Editors (ICMJE) criteria
for authorship of this manuscript, take responsibility
for the integrity of the work as a whole, and have
given final approval to the version to be published.
Open Access: This article is published under the
Creative Commons Attribution Noncommercial License,
which permits any noncommercial use, distribution,
adaptation, and reproduction provided the original
author(s) and source are given appropriate credit.
Received: September 19, 2016
Accepted: December 6, 2016
Citation: Oncology & Hematology Review,
2017;13(1):56–8 Corresponding Author: Ignacio Mendoza, ENT-
Head and Neck Surgery Service, General Hospital of
Concepcion, San Martin Av. 1436; Concepcion, Chile.
Synovial sarcoma (SS) is a malignant soft tissue tumor, which represents about 10% of all soft
tissue sarcomas. 1 It occurs most often in the lower extremities of young men, and is very rare
in the head and neck region, with an incidence of about 2–4%. 2,3 The origin of the SS remains
uncertain, although it is believed that its origin would be in undifferentiated stem cells and tissue
that are related neither to ultrastructural, nor to histological synovial tissue, being only <5% intra-
articular. 4 Typically, it affects patients between 14 and 35 years of age, and its clinical presentation
includes the presence of a neck mass, hoarseness, dysphagia, and dyspnea. 5 When it is presented
in the head and neck (HN) it seems to have better prognosis than in the extremities, with five-year
survival for head and neck between 47% and 82%. 6 The first report in HN was in 1954, 7 and the
most frequent location has been in hypopharynx and lymph nodes. Other locations are reported in
parotid gland, paranasal sinuses, larynx, pharynx, and the retropharyngeal space. 2,8 There are only
few reports of SS in infratemporal fossa. 4,9–13 The optimal treatment has not been established, but
complete resection with or without radiotherapy and chemotherapy is currently considered the
best available therapy. Here is a case of synovial sarcoma located in the left infratemporal fossa.
We describe its diagnosis, therapeutic confrontation, and evolution.
A 32-year-old man showed at the dental office in March 2014, due to pain in his left mandibular
temporomandibular joint with about 3 months of evolution. Bruxism was diagnosed and a plane
relaxation for 3 months was prescribed; however, the patient did not experience a good response.
In June 2014 he was referred to a maxillofacial surgeon who confirmed a volume increase in the
left zygomatic region (see Figure 1). A computed tomography (CT) scan was performed, revealing
a multilobulated large, aggresive, expansive, and destructive heterodense solid mass centered
in the left masticatory space. The lesion also involved the oval foramen, ipsilateral infratemporal,
and pterygopalatine fossa. There was osteolitic compromise of the mandible, temporomandibular
join, pterygoid process, middle cranial base, and sphenoid wing. At its largest diameter, the lesion
measured 8 cm and enhancement was seen following intravenous contrast administration with
central hypodense areas suggestive of necrosis. Lymphadenopathy was observed with hypodense
center in the II ganglionar level as large as 10 mm were present (see Figure 2C).
Subsequently, a magnetic resonance imaging (MRI) study was performed revealing in T1 sequence
a solid isointense expansive process warping the posterior wall of the maxillary sinuse and
56 TOUCH ME D ICA L ME D IA