soft tissue sarcomas are rare tumors ( 1% of all adult malignancies ) with a dismal prognosis .
approximately 70% of sarcomas occur in the extremities ( 49% in the lower and 19% in the upper limbs ) , while the remaining 30% occur in the trunk , abdomen or retroperitoneum ( 1,2 ) . among the most common histological types of sarcomas of the extremities , malignant fibrous histiocytoma ( mfh )
is the one exhibiting the highest incidence , followed by liposarcoma , fibrosarcoma and neurofibrosarcoma , with a peak incidence in the sixth decade of life . according to the world health organization 2002 classification of soft tissue tumors ( 3 )
, mfh may be categorized into three morphological subtypes : i ) storiform - pleomorphic mfh ( undifferentiated high - grade pleomorphic sarcoma ) ; ii ) giant - cell mfh ( undifferentiated pleomorphic sarcoma with giant cells ) ; and iii ) inflammatory mfh ( undifferentiated pleomorphic sarcoma with prominent inflammation ) ( 3 ) .
mfh is also considered by the american joint committee on cancer to be a high - grade sarcoma by definition and , therefore , exhibiting high local aggressiveness .
the typical histological appearance of mfh is that of a hypercellular neoplasm , with marked nuclear and cytological pleomorphism , bizarre appearance of stromal cells and a fascicular or storiform model growth ( 4 ) .
the presence of a lesion suspicious for soft tissue sarcoma should prompt the surgeon to perform diagnostic - instrumental tests .
x - ray may reveal ectopic calcifications in the surrounding tissues ( 520% ) , sclerosis or clear erosion of adjacent bone due to tumor compression .
magnetic resonance imaging ( mri ) may reveal a lobulated mass , with intermediate signal in both t1 and t2 images ( 5,6 ) .
there are also frequent intracapsular areas of tumor necrosis and hemorrhage , which are occasionally so extensive that the tumor is mistakenly diagnosed as hematoma of the soft tissues ( 7 ) .
a correct surgical approach is crucial in several tumors , as previously demonstrated by our studies ( 8,9 ) , and a survey of the literature suggests that surgery is the first choice for the treatment of mfh ( 10 ) .
owing to advances in surgical techniques , the advanced reconstructive methods and the development of effective adjuvant therapies , the use of widely demolitive surgery is now considered unnecessary . over the last few decades
, studies have demonstrated that conservative surgery , with or without adjuvant therapy , appears to be an effective treatment for sarcomas , including high - grade sarcomas , with a local recurrence rate of 715% , with no significant differences in terms of overall survival and disease - free interval compared with amputation ( 1113 ) .
neoplastic infiltration of the resection margins at the end of surgery appears to be among the major factors affectng the rate of local recurrence .
in fact , the local recurrence rate approximates 13% with margins of < 1 cm , while it may be reduced to 0% in cases with margins of > 1 cm . in light of these data
, amputation may no longer be considered to be the primary approach for the treatment of sarcomas of the limbs , but rather be reserved for those cases in which adequate resection can not be achieved without severe aesthetic and functional deficits , or when the sarcoma is very proximally located in the limb .
the functional compartmental resection represents the surgical evolution of amputation , although not without functional consequences .
however , the literature over the last 20 years reveals that soft tissue sarcomas of the extremities and precisely localized within a muscle may be treated by excision of the entire affected muscle , with preservation of the surrounding innervated muscles , without performing total compartmental resection ( 14 ) .
the present study stems from a multidisciplinary management involving a team with expertise in general microsurgery , where microsurgical technique is routinely applied by the use of magnification devices such as loupes 4.5 , operating microscope 440 , dedicated instruments and led coaxial light .
a 79-year - old caucasian man presented with a swelling in the middle third of the dorsal aspect of the left forearm .
a core needle biopsy previously performed in a different hospital had not reached a definitive diagnosis .
the patient also reported history of trauma 6 months earlier , with progressive volume increase , without pain or functional deficit . on clinical examination ,
the patient had a tense elastic 5-cm swelling in the dorsal aspect of the left forearm ( fig .
1 ) , hypomobile in the deep region , while the overlying skin appeared to be normal .
the tinel 's sign and other tests assessing the functionality of the muscles and tendons of the hand and fingers were negative .
the patient reported a dull pain elicited by palpation of the region in question and was subjected to instrumental diagnostic examinations .
ultrasound imaging revealed a heterogeneous lesion with hyperechoic areas , perilesional hypervascularization and intralesional spots on signal - enhanced color doppler sonography .
an mri revealed a neoformation sized ~84 cm within the extensor digitorum communis ( edc ) muscle , without invasion of the interosseous space ( fig .
furthermore , the patient was subjected to total - body computed tomography ( ct ) staging that was negative for lymph node involvement or distant metastases .
finally , electromyography ( emg ) was performed with normal findings , thus excluding any nerve compression or infiltration . as the case history
, physical examination and diagnostic tests were strongly suggestive of a tumor , we decided to perform an open biopsy according to the criteria of enneking et al ( 15 ) .
this procedure was performed under temporary ischemia of the arm , applying a tourniquet for 20 min at 220 mmhg at the root of the arm .
the bioptic specimen included skin , subcutaneous tissue , fascia , muscle and a portion of the tumor that appeared to be localized inside the muscle .
on histological examination , the neoformation exhibited irregular margins and consisted of spindle cells with nuclear atypia set in a dense , sclerotic , richly vascularized stroma , as evidenced by cd34 staining .
on immunohistochemical staining , the tumor was positive for cd68 and negative for smooth muscle actin ( sma ) and s-100 .
the proliferative index , as assessed by ki-67 , was 40% of the neoplastic elements .
thus , the final diagnosis was mfh . based on the histological findings , mri imaging and in accordance with the national comprehensive cancer network ( nccn ) guidelines ( 16 )
, we decided to remove the tumor by excising the extensor compartment of the forearm with subsequent tendon transfer .
indeed , the guidelines suggest radical surgical treatment followed by radiotherapy for such soft tissue sarcomas .
a wide longitudinal incision was performed that also removed the scar of the earlier biopsy ( fig .
surgery was performed by a microsurgical technique under magnification ( loupes 4.5 ) and the use of dedicated instruments and bipolar coagulator , allowing the identification of the correct anatomical cleavage planes and the preservation of the sensory branches of the radial nerve . according to the mri findings
, the tumor was considered to be localized within the edc muscle ; however , the surgical exploration revealed that the lesion was located at a deeper plane , within the abductor pollicis longus muscle ( apl ) .
the muscle fibres appeared to be subverted and discontinued , while the apl muscle sheath did not exhibit macroscopic discontinuity or pathological adhesions to the adjacent and overlying muscles ; the underlying bones did not appear to be infiltrated ( fig .
3 ) . therefore , we decided to change the surgical strategy and perform a wide excision of the tumor , including the apl muscle , without discontinuing the intact muscle sheath and the tumor pseudocapsule ( fig .
4 ) , thus preserving the edc muscle . subsequently , through a palmar mini - incision , we performed a transfer of the palmaris longus ( pl ) tendon to the distal apl metacarpal tendon insertion with a pulvertaft suture , in order to restore the abduction function of the thumb .
the histological examination revealed an encapsulated , whitish neoformation , sized ~94.5 cm , with regular margins .
5 ) with nuclear atypia set in a dense , sclerotic , richly vascularised stroma , as evidenced by cd34 staining . on immunoistochemical staining ,
the proliferative index , as assessed by ki-67 , was 40% of the neoplastic elements .
the mfh was classified as stage iib ( pt2b , pn0 , pm0 , g2 and r0 ) according to the american joint committee on cancer ( 7 ) .
after 2 weeks , the recovery of the strength and functional ability of the hand and thumb was satisfactory , compared to the contralateral side .
after 2 months of rehabilitation , there was no functional deficit in the abduction of the thumb .
in accordance with the nccn guidelines ( 16 ) , we consulted the oncologist and the radiologist , who did not suggest any adjuvant therapy , also taking into consideration the patient 's comorbidities ( prostate cancer , heart disease and chronic obstructive pulmonary disease ) .
moreover , the patient was informed of the options of adjuvant radiation therapy vs. observation and he selected observation .
the patient has been followed up every 6 months for 4 years with clinical and instrumental examinations and he remains alive and recurrence - free .
the diagnosis of soft tissue sarcomas located in the extremities is frequently delayed , as the tumor often grows slowly and is not associated with specific symptoms , apart from tension in the movements of the limb . in the present case ,
the open biopsy according to the criteria of enneking ( 15 ) established the diagnosis of mfh .
the biopsy usually represents a strategy and not a small surgical intervention , therefore it is essential to first perform ultrasound , mri or ct examinations to limit the risk of a biopsy procedure .
a biopsy performed incorrectly may negatively affect subsequent therapy , increasing the risk of local recurrence and postoperative complications , worsening the functional outcome . according to the mri findings
therefore , surgery was planned to excise the tumor along with the edc , which would mean complete detachment of digit tendons and severe functional damage .
accurate surgical dissection allowed us to identify the incorrect localization diagnosed by mri , i.e. , the sarcoma was unusually and unexpectedly located within the apl muscle .
therefore , we performed a wide excision of the sarcoma , including the apl muscle , without discontinuing the intact muscle sheath and the tumor pseudocapsule , preserving the edc muscle .
simultaneous pl tendon transfer was performed , to restore the abduction function of the thumb .
the surgical excision and reconstruction were performed by the same microsurgical team through the application of a microsurgical technique and the functional outcome was excellent .
the follow - up at 4 years did not reveal tumor recurrence or metastatic spread . in conclusion ,
when the sarcoma is entirely enclosed within a muscle , with free margins and without regional or distant metastases , a wide excision maintaining the muscle sheath intact may be considered as the optimal treatment .
 soft tissue sarcomas are rare tumors with a dismal prognosis . among the most common histological types of sarcomas of the extremities , malignant fibrous histiocytoma ( mfh ) 
 is the one with the highest incidence . 
 surgery is considered to be the first choice of treatment for mfh . to the best of our knowledge , 
 this is the first case report in the literature of a patient with mfh within the abductor pollicis longus ( apl ) muscle . 
 this unusual location was also unexpected by the treating surgeons , as the preoperative magnetic resonance imaging localized the tumor inside a different muscle . a 79-year - old caucasian man presented with a swelling in the middle third of the dorsal aspect of the left forearm . 
 mfh was diagnosed following biopsy and instrumental diagnostic examinations . surgical excision and simultaneous reconstruction 
 was performed by the same microsurgical team , achieving an excellent functional outcome . 
 the present case highlights the significance of microsurgical approach for improving strategic planning in oncologic surgery . 
 accurate surgical dissection , performed by a team of microsurgeons , allowed for the identification of the unusual and unexpected tumor localization within the apl muscle . for this reason , a change of surgical strategy allowed for preservation of the extensor digitorum communis muscle , which would otherwise have to be resected , with tendon transfer and successful restoration of the thumb abduction function . 
Introduction
Case report
Discussion