Introduction:
Synovial sarcoma is a rare type of spindle cell tumor that constitutes
approximately 10% of all soft tissue sarcomas (1).Despite its name,
which originates from the microscopic resemblance to developing
synovium, the exact origin of this tumor remains unknown. Sarcomas in
the head and neck region are exceptionally uncommon, accounting for
merely 1% of all primary tumors in this area and 4-10% of sarcomas
overall (2, 3). The majority of head and neck sarcomas (around 80%)
arise from soft tissues, while only a minority (20%) originate from
bone or cartilage (2, 4). These tumors originate from mesenchymal cells,
encompassing a diverse group that can arise from various tissues such as
bone, cartilage, muscle, fat, blood vessels, and nerves (3).
Synovial sarcoma exhibits a higher prevalence in the third decade of
life, primarily affecting teenagers and young adults between the ages of
15 and 40 (5). When synovial sarcoma arises in the maxillary, it
presents a unique diagnostic challenge due to its rarity. Diagnosis
becomes particularly challenging when the tumor is small, as it tends to
grow slowly and manifest with nonspecific symptoms (6). The complex
anatomy of the head and neck region also poses limitations in achieving
wide surgical margins, which contributes to increased local recurrence
rates and poorer disease-specific survival compared to sarcomas in other
anatomical sites (7).Therefore, complete resection is considered the
optimal treatment approach for synovial sarcoma (8).
In this article, we present a challenging diagnostic case report of
synovial sarcoma in the maxilla. We aim to shed light on the intricacies
of diagnosing and managing this rare condition, emphasizing the
importance of early detection and comprehensive surgical intervention
for improved patient outcomes.
Case Presentation :
In September 2021, a 6-year-old female patient presented to the
Maxillofacial Surgery Department of Mashhad University of Medical
Sciences with a complaint of swelling at the left posterior sites of the
maxilla. The patient’s medical history was unremarkable. Upon clinical
examination, a soft, darker-colored lesion was observed in the buccal
and palatal regions, extending from tooth E to approximately the
midline. The macroscopic examination revealed a large piece of soft,
tumoral tissue along with multiple shapeless soft and jelly-like pieces.
The largest piece measured 30×22×8 mm with an irregular surface, while
the smaller pieces collectively measured 7×22×32 mm. An incisional
biopsy was performed, and a soft tissue specimen was sent to the
pathologist for further evaluation. Microscopic examination of serial
sections from the submitted sample revealed a malignant proliferation of
dysplastic changes and multiple mitoses of spindle cells.
Immunohistochemical (IHC) analysis showed negativity for neural ,
muscular , plasma cell and epithelial markers, including Myogenin, SMA,
SOX10, CD34, and EMA. However, the tumor exhibited positive expression
of Vimentin, Bcl-2, and particularly TLE1 markers.
Based on the morphologic and IHC findings, a diagnosis of synovial
sarcoma was established and the diagnosis was further supported by a
40% Ki67 proliferative index. Figure 1 illustrates the hematoxylin and
eosin staining and immunohistochemical analysis of the synovial sarcoma
sample. The patient was referred for further evaluation and treatment
planning to determine the optimal management strategy for the synovial
sarcoma.
Furthermore, the treatment strategy for synovial sarcoma was
meticulously devised. Given the complexity of the tumor’s location, a
surgical approach was chosen as the primary intervention. The surgical
procedure aimed at achieving complete resection with clear margins,
thereby minimizing the risk of local recurrence. However, due to the
challenging anatomical constraints of the head and neck region,
obtaining wide surgical margins can be intricate. To enhance the
treatment’s effectiveness and address potential residual microscopic
disease, a multimodal approach was adopted. This encompassed a
combination of surgery and adjuvant radiotherapy. The integration of
radiotherapy aimed to target any remaining cancer cells while also
acting as a preventive measure against possible recurrence. This
comprehensive treatment approach was tailored to not only address the
immediate tumor but also to ensure long-term disease control and optimal
patient outcomes.
After the completion of treatment, meticulous follow-up was conducted to
monitor the patient’s progress. The patient underwent regular clinical
assessments and imaging studies. Encouragingly, at the one-year
follow-up mark, no evidence of disease was observed.
Discussion :
Synovial sarcoma is a rare malignancy primarily affecting the
extremities, with its occurrence in the maxillofacial region being
exceptionally rare. The unique anatomical location of synovial sarcoma
in the maxillofacial region poses significant diagnostic and therapeutic
challenges (9). In our case, a 6-year-old female presented with a
swelling in the left posterior sites of the maxilla. The
histopathological examination revealed morphologic features consistent
with synovial sarcoma. The confirmation of synovial sarcoma was further
supported by immunohistochemical analysis, which showed positivity for
vimentin, bcl2, and Tle1 markers. Despite ongoing debates regarding the
specificity and diagnostic significance of the Tle1 staining test, a
systematic review has validated its sensitivity and specificity as a
marker for synovial sarcoma. Additionally, it’s suggested that this
marker might hold direct relevance to the disease’s pathophysiology(10).
The treatment approach involved surgery for complete resection followed
by adjuvant radiotherapy to prevent recurrence. After treatment, regular
follow-up assessments and imaging were conducted and at the one-year
follow-up, no evidence of disease was observed. Synovial sarcoma is
characterized by its biphasic histology, comprising epithelial and
spindle cell components. However, our case demonstrated a predominantly
spindle cell pattern. This variant, known as monophasic synovial
sarcoma, is less common but has been reported in the literature (11,
12). The diagnosis of synovial sarcoma in the maxillofacial region
requires careful consideration of the histopathological features, along
with the characteristic immunohistochemical profile. Similar cases of
synovial sarcoma in the maxillary region have been reported in the
literature.
We meticulously reviewed a collection of 9 cases of synovial sarcoma in
the maxillary region from the literature (9, 13-18), all of which are
concisely summarized in Table 1. The patient age range spanned from 26
to 79 years, with an average age of 46.5 years and a male-to-female
ratio of 5:4. However, our case adds a distinctive facet as we detail an
exceptionally rare occurrence in a 6-year-old girl. Among these 9 cases,
3 manifested in the parotid gland (13), 4 in the maxillary and paranasal
sinuses (9, 14, 16, 17), 1 in the nasal septum (18), and 1 in the
maxilla (15)– resembling our presented case. Surgical intervention was
universally applied, with 6 instances followed by adjuvant radiotherapy
(9, 13, 14, 16, 17), 1 with post-recurrence radiotherapy (13), and 3
receiving chemotherapy as supplementary treatment (14-16). Another
single case was managed solely with surgery (18), while the remaining 8
involved a combination of surgery, radiotherapy, and/or chemotherapy.
Correspondingly, our case underwent surgery followed by adjuvant
radiotherapy. Among the 3 cases that underwent chemotherapy, Maxymiw et
al. (15) elucidated the regimen (three cycles of doxorubicin,
cyclophosphamide, and vincristine), while Saito et al. (16) adopted
three courses of ifosfamide and pirarubicin; both regimens achieved
tumor mass reduction. Nonetheless, Lin et al.’s (14) case omitted
precise details on the chemotherapy protocol. The average follow-up span
extended to 28 months, with 2 out of the 9 cases dying within 8 and 96
months. Maxymiw et al.’s case resulted in death due to neuropathy and
multiple system failure (15), while Kartha et al.’s case did not specify
the cause of death (13). Additionally, 3 cases experienced recurrence
within 1 month to 4 years (13, 14), though they remained alive.
Conversely, other cases showed no evidence of disease during the
follow-up period.
It’s important to note that the case we present is a singular case
report, and its follow-up period remains relatively short. Analogous to
synovial sarcomas affecting extremities, metastasis or local recurrence
can manifest after a certain interval. Consequently, we are closely
monitoring the progress of our current patient.
From the patient’s perspective, undergoing treatment for synovial
sarcoma in the maxillary region was a complex journey, particularly
given the young age at diagnosis, which was emotionally challenging.
However, post-treatment, the absence of complications following surgery
and radiotherapy sessions and the complete disappearance of disease
symptoms have brought a sense of relief and optimism. The patient is now
in the process of receiving prosthetic treatment, a significant step
towards regaining normalcy and overall well-being.
The management of synovial sarcoma involves a multidisciplinary approach
due to its aggressive nature and potential for local recurrence and
distant metastasis (19). Surgical excision remains the mainstay of
treatment, aiming for complete resection with clear margins. However,
the extent of surgery in the maxillofacial region may be limited by the
proximity of vital structures. The rarity of synovial sarcoma in the
maxillofacial region poses challenges in developing standardized
treatment guidelines. The optimal therapeutic approach should be
tailored to each individual case, considering factors such as tumor
size, location, histological subtype, and the patient’s overall health.
Close collaboration between various specialties, including maxillofacial
surgeons, pathologists, oncologists, and radiation therapists, is
essential to provide comprehensive and personalized care to patients
with synovial sarcoma in the maxillofacial region.