undifferentiated pleomorphic sarcoma ( ups ) , formerly known as malignant fibrous histiocytoma ( mfh ) , is a common soft tissue sarcoma in which any attempt to describe the line of differentiation fails .
ups was first described by ozzello et al . in 1963 , and feldman and norman first described primary malignant tumor of bone in 1972 ( quoted from ) .
it most commonly involves the extremities and retro - peritoneum . in the head and neck region ,
the most commonly affected sites are the nasal cavity and the paranasal sinuses ( 54.3% ) .
the mandible is a rare location , accounting for only 3% of tumors within bones .
ups of head and neck that extend into bony structures are associated with a much more aggressive clinical course than those that are restricted to soft tissues . in this article , we report a rare case of ups of the mandible in a 44-year - old korean man .
a 44-year - old man was referred to dankook dental hospital from a local neurosurgery clinic .
the patient presented with the chief complaint of a rapidly growing mass in the left mandible area within the last two months .
extra - oral examination revealed a tender , 4 to 5 cm sized solid mass in the left mandible area .
no specific lesion such as ulcer or infection was found in intra - oral examination .
the patient s medical history was non - contributory and there was no history of trauma or dental treatment recently .
nothing remarkable was found through laboratory data including complete blood count , urine analysis , or chest x - ray in the preoperative exam .
preoperative panoramic radiographs showed an ill - defined radiolucent , radiopaque mixed lesion on the left mandible area ( fig .
1 ) . a neck computed tomography ( ct ) with contrast revealed a 4 cm heterogeneously enhancing mass lesion in the left mandible body extending to adjacent soft tissue with bony destruction .
2 ) . positron emission tomography - computed tomography ( pet - ct ) revealed a large lobulating hypermetabolic lesion in and around the left submandibular area with possible bone invasion . in both lungs ,
a few tiny nodular opacities were seen , but these were too small to be characterized ( fig .
3 ) . with a clinical diagnosis of malignant tumor of the mandible , surgery was performed . under general anesthesia , a mandibulectomy from the symphysis to the left ascending ramus was performed , and reconstructed with vascularized osteocutaneous fibula free flap .
to stabilize the flap , inter - maxillary fixation with arch - bar was applied in right half maxilla and mandible ( fig .
the main tumor mass , with hematoxylin and eosin staining , was highly vascular and hypercellular with an apparent whitish slit - like hemorrhagic space at 100 magnification . at 200 magnification , tissue presented generalized myxoid pattern with a loose matrix .
the tumor consisted of fibroblast - like spindle - shaped cells , specifically osteoclast - like giant cells with remarkably active mitosis . at high - power field ( 400 magnification ) , nuclear pleomorphism with prominent nuclei that varied in size , figure , and
postoperatively , the patient was referred to the department of hemato - oncology for adjuvant chemotherapy .
upon examination at two months , metastasis to the lung and local recurrence on primary mandible area was detected in pec - ct .
thus , metastatectomy was performed for metastasis of lung , and the patient is receiving continuous palliative chemotherapy .
the older term for ups was mfh , based on the resemblance of the cells to histiocytes and fibroblasts ( due to their elongated shapes ) .
the name was modified to ups because the morphologic pattern of mfh is similar to many other sarcomas .
the usual presentation in the literature is a painful mass that expands over a few weeks or months . in our case , the patient was a male in his forties , complaining of a rapidly growing painful mass .
non - specific symptoms such as paresthesia make diagnosis of the tumor by clinical symptoms difficult .
this implies that some of these tumors may represent an initial proliferative response to trauma .
ups is either primary or secondary , and secondary tumors are more aggressive and less common than primary tumors .
park et al . reported in a review that ct and magnetic resonance imaging ( mri ) features of ups of head and neck are nonspecific .
on ct scans , ups appears as a non - specific , large , lobulated , soft tissue mass iso - attenuated to muscle .
central areas of low attenuation may be due to necrosis , hemorrhage or myxoid material . in 5% to 20% of the cases , calcification or ossification can be detected . on mri , ups shows a heterogeneous hyper - intense pattern on t2-weighted images and isointensity that is almost same as muscles on t1-weighted images .
non - immunoreactivity for pan - ck , ck8 , ck18 allows sarcomatoid or anaplastic hepatocellular carcinoma and cholangiocarcinoma to be ruled out .
angiosarcomas are excluded due to no reactivity for the usual vascular antigens , such as cd31 , cd34 .
liposarcoma or malignant peripheral nerve sheath tumor ( s-100 ) , rhabdomyosarcoma ( desmin ) , malignant melanoma ( s-100 and hmb-45 ) , malignant lymphoma ( lca ) are also excluded .
s100 , desmin , s-100 , hmb-45 , lca in parenthesises are antibody of liposarcoma , rhabdomyosarcoma , malignant melanoma , malignant lymphoma respectively .
fine needle aspiration biopsy can be used for obtaining of biopsy samples , but sensitivity is poor , ranging from 60% to 80% .
this is due to the inability to obtain immunohistochemical stains on most samples from fine needle aspiration biopsy .
the management of ups of the mandible requires early radical surgery including removal of adjacent normal tissue , with a minimum of 3 cm tumor - free margins .
elective neck dissection is performed only when there is an evidence of cervical lymph node metastasis .
the patient should be re - examined often to rapidly detect local recurrence and distant metastasis .
the efficacy of chemotherapy and radiotherapy treatment for ups of mandible is not well established .
this is based on randomized trials comparing surgery with or without radiotherapy that demonstrate the efficacy of radiotherapy as an adjuvant treatment in decreasing local recurrence rates .
adjuvant radiotherapy may be indicated for patients with probable insufficient surgical margin when re - resection is not possible .
one observer noted that cyvadic did not improve the prognosis , and a more intensive regimen could have been more effective .
therefore , if adjuvant chemotherapy is needed , more intensive chemotherapy might be employed only for the high - risk group such as tumors with history of local recurrence and histologically high - grade because of possible subclinical or microscopic metastasis .
perhaps 25% to 35% of patients with ups of head and neck region will develop metastases , with the lungs as the most common metastatic site from ups in the head and neck , followed by bone and liver .
in this case , we detected no lymph node metastasis at the pre - operative examination so we did not perform neck dissection .
this infiltrative growth is an adverse prognostic factor not only for local control , but also for disease - free and meta - stasis - free survival .
tumor infiltration into adjacent soft tissue including muscles occurred in this case , accompanied by local recurrence .
background ( primary or recurrent ) , histologic grade , tumor size , and surgical margin are the significant prognostic factors for the outcome after surgical treatment . in conclusion , the diagnosis of ups should be reserved only for those cases in which any attempt to identify a line of differentiation has failed .
due to the low numbers of patient with ups of the head and neck region , a consistent therapeutic strategy for this disease is unlikely to be established .
 undifferentiated pleomorphic sarcoma ( ups ) , previously known as malignant fibrous histiocytoma , occurs commonly in the soft tissues in adult , but is rare in the maxillofacial region . 
 it consists of undifferentiated mesenchymal tumor cells resembling histiocytes and fibroblasts . 
 the purpose of this article is to report a case of ups in the mandible . a 44-year - old patient presented with a painful growing mass in the mandible of two months duration . computed tomography and 
 positron emission tomography - computed tomography revealed an ill - defined heterogenous , hypermetabolic mass about 4 cm in size in the left mandible invading adjacent soft tissues . 
 a left mandiblulectomy and reconstruction with a fibular free flap were performed . 
 immunohistochemical study gave a diagnosis of ups . 
 the patient was referred for adjuvant chemotherapy after surgical removal of the tumor . 
Introduction
Case Report
Discussion