Myofibromas of the oral cavity

A rare low-grade myofibroblastic sarcoma in lower jaw with the resemblance to benign lesions

Background

Low-grade myofibroblastic sarcoma (LGMS) is a rare solid infiltrative soft tissue tumor with a predilection for the head and neck region.

Case presentation

We report the diagnostic steps of a fast-growing lesion of the lower left jaw in a 45-year-old otherwise healthy woman. A first biopsy and subsequent histopathological examination showed potential differentials of a benign myofibroma, benign nodular fasciitis or an LGMS. This diagnostic overlap was a challenge for the decision of the further treatment approach. The treatment consisted of a segmental en bloc resection of the mandible including the second premolar, first and second molar. Histopathological examination of the resected tumor confirmed an LGMS.

Conclusion

The histopathologic resemblance of LGMS to a range of benign and reactive tumors may lead to misdiagnosis and mistreatment. The rarity of LGMS explains the lack of established treatment protocols. This case shows the importance of adequate clinical decisions, expertise in the histopathology of rare tumors and interdisciplinary exchange to achieve state-of-the-art patient management.

Mandibular Myofibroma and Severe Trismus: A Complex Case and Review of Complications

A female child was investigated for insidious onset of temporomandibular joint dysfunction and trismus in the setting of a mandibular myofibroma. Myofibromas, benign mesenchymal neoplasms composed of spindle cells, are rarely found in the oral cavity, most commonly in the mandible. These lesions are historically described as indolent with a high cure rate and minimal recurrence rates following surgical resection. The patient initially presented with concerns regarding snoring, retrognathia, and jaw ankylosis, as well as a history of trouble latching as an infant but without obvious physical deformities. Imaging revealed a large expansile lytic mass of the mandible, but no temporomandibular joint involvement; surgical biopsy evidenced myofibroma, and the lesion was resected. Over the course of disease, the lesion continued to expand, and the patient’s maximal incisal opening continued to decrease despite conservative management with jaw physiotherapy; eventually she could not open her mouth despite the absence of joint involvement. Re-exploration along with formal jaw physiotherapy was achieved and optimal jaw opening was maintained. Myofibromas are rare benign desmoid tumors that can present anywhere in the body in solitary and multicentric forms, and previously did not present significant challenges to surgical and medical management. Tumors of the mandible may present with trismus and soft tissue ankylosis, which can mimic temporomandibular joint dysfunction in the absence of joint involvement. Physical therapy, rehabilitation, and soft tissue contracture release are key to management and improving outcomes in oral cancer patients, regardless of tumor pathology.

Congenital granular cell epulis: a rare paediatric tumour of newborn

Congenital granular cell epulis is a congenital growth rarely found on the gingiva of neonates. These remarkably large tumours present in an infant's mouth may impede with feeding, respiration or adequate mouth closure. Recognition of this entity and prompt treatment are essential for preventing any difficulties for the neonate. This is a case report of a 35-day-old female neonate who presented with a single exophytic lesion in the maxillary alveolar ridge. The differential diagnosis, management regimens and complications of this condition are reviewed. The lesion was excised under intravenous sedation and subjected to histopathological analysis. Based on the microscopic findings, the diagnosis of congenital granular cell epulis was confirmed. Clinicians including paediatricians, sonographers, dentists and surgical pathologists should be able to timely recognise and intervene such tumours as they may be potentially harmful to the infant.

Infantile myofibromatosis treated by mandibulectomy and staged reconstruction with submental flap and free fibula flap: a case report

BACKGROUND

Infantile myofibromatosis is the most common benign fibrous tumor in infants. Three different types have been reported in the literature. The most commonly affected areas are the head, the neck and the trunk. Our patient showed a very high level of mandibular destruction resistant to all mandibular sparing treatment strategies requiring segmental mandibulectomy and complex reconstruction.

CASE PRESENTATION

We describe a rare case of multicentric infantile myofibromatosis with mandibular bone destruction. The treatment required a succession of chemotherapy, a subtotal transoral resection and a hemi-mandibulectomy. The mandibular reconstruction was staged with initial bridging titanium plate with a submental flap, followed later by a fibula free flap.

CONCLUSION

Mandibular involvement by myofibromatosis is rare, and the extend of bone destruction and reconstruction make this case unique. To our knowledge, this is the only reported case of fibula free flap mandibular reconstruction in a patient with infantile myofibromatosis , as well as one of the youngest reported submental island flaps for any pathology. We describe the clinical presentation and management, including relevant imaging, histopathology, medical and surgical treatment as well as a review of relevant literature.

Central myofibroma of the maxilla

Myofibroma is a rare benign localized or generalized proliferation of myofibroblastic tissue occurring mostly in infants or children. In the oral region, most lesions occur in the mandible, lip, buccal mucosa, and tongue; however, the lesions arising in the maxilla are very rare. Myofibroma has an aggressive clinical presentation and is often treated aggressively because of an inappropriate diagnosis. A unique feature of central myofibroma of the jaws is the potential for teeth and other odontogenic structures to be involved by tumor. We report a case of myofibroma arising in the left side of the maxilla of a 12-year-old girl and describe the differential diagnosis from other spindle cell lesions of neural and smooth muscle origin. We treated the case using surgical excision under general anesthesia. Immunohistochemical staining was done for establishing the diagnosis since histopathological diagnosis with conventional staining could not distinguish myofibroma from spindle cell tumors.

Myofibroblastoma of the mandible in a 3-year-old child

Myofibroblastoma is a rare benign tumor of the head and neck region, which is characterized by a large, rapidly growing, and destructive mass. A 3-year-old boy presented with an 8-week history of a rapidly growing swelling of the right mandible. Examination revealed a firm 13-cm mass occupying the entire right body and ramus of the mandible. The clinical and radiological features were suggestive of a sarcoma. An initial biopsy taken in the referring hospital was inconclusive, and the second biopsy showed a myofibroblastic neoplasm consistent with a desmoplastic fibroma. Progressive tumor growth necessitated a tracheostomy. Right hemimandibulectomy was performed, and the defect was reconstructed with free microvascular fibula flap. Histopathology and immunocytochemistry revealed a myofibroblastoma. This entity differs from other myofibroblasts and fibroblast tumors such as inflammatory myofibroblastic tumor (IMT), myofibroma, and desmoplastic fibroma. The child has been followed up for 2 years.

CONCLUSION

Differentiation between myofibroblasts and fibroblastic tumors as well as some malignancies can be challenging. Myofibroblastoma can behave as a malignant neoplasm, and the clinical distinction of this entity lies primarily in its recognition as a benign neoplasm.

Head and neck solitary infantile myofibroma: Clinicopathological and immunohistochemical features of a case series

Infantile myofibroma is a rare mesenchymal benign tumor mostly found in the head and neck region. The aim of this study was to describe a small case series of head and neck solitary infantile myofibroma, emphasizing the importance of the histopathological and immunohistochemical features, and the potential diagnostic challenges. For the study, clinical and imaging data were obtained from the medical records. All cases were histologically reviewed, and immunohistochemical analyses were performed to confirm the diagnosis. Four cases of head and neck solitary infantile myofibroma were identified. All patients were females and presented a mean age of 3 years old (ranging from 2 to 6 years). The site of the tumors were the mandible, right cheek, subcutaneous tissue adjacent to basal cortical of the mandible and upper anterior gingiva. No symptoms, such as pain or paresthesia, were reported. Computerized tomography revealed well-delimited tumors. All tumors were positive for vimentin and alpha-smooth muscle actin. All patients underwent surgical excision and no signs of recurrence were observed after long-term follow-up. In summary, head and neck solitary infantile myofibromas are rare and present excellent prognosis. The correlation between clinical, histopathological and immunohistochemical features are essential for a correct diagnosis.

Solitary myofibroma of the mandible: an immunohistochemical and ultrastructural study with a review of the literature

A solitary myofibroma (MF) is an unusual spindle cell neoplasm that usually arises in the soft tissue, skin, or bone of the head and neck region in infancy. We report an extremely rare case of MF of the mandible in an 18-year-old Japanese woman together with the conventional histologic, immunohistochemical, and electron microscopic findings. The tumor was well circumscribed and composed of fibroblast-like or myofibroblast-like spindle cells. On immunohistochemical evaluation the tumor cells were positive for vimentin, α-smooth muscle actin, HHF-35, and calponin, but negative for neurogenic antigens and markers for vascular endothelial cells. The Ki-67 labeling index was 10 % and the p53 labeling index was 10 %. Ultrastructural examination revealed smooth muscle cell differentiation. The patient was treated by surgical resection and underwent follow-up without any signs of recurrence. MF presents a wide range of differential diagnosis, including benign and malignant neoplasms. Therefore, accurate diagnosis may avoid an unnecessarily aggressive therapy.

Intraosseous myofibroma of mandible: A rarity of jaws: With clinical, radiological, histopathological and immunohistochemical features

Myofibroma is an uncommon benign mesenchymal neoplasm composed of myofibroblasts, but it can be confused with more aggressive spindle cell tumors. Solitary myofibroma is common in soft tissues of head and neck, but rare in the jaw bones with only 38 cases of central myofibroma of mandible reported in English medical literature. When encountered in the jaws, lesions exhibit clinical and radiographic features suggestive of odontogenic cysts/tumors or other neoplastic conditions. We hereby present the 39^th case of intraosseous myofibroma of the mandible which had been reported to our institution. A 16-year-old male reported with a chief complaint of swelling in the right side of face. Intraorally there was a firm, nontender swelling in the right buccal aspect of the mandible. Radiologically the lesion was osteolytic, destroying the buccal cortical plate. Histologically, characteristic biphasic pattern of myofibroma was noticed. Immunoreactivity was positive for vimentin and αSMA but negative for desmin, thus confirming our diagnosis. The patient was treated by local-wide surgical excision of the lesion. A 3-year follow-up revealed no signs of recurrence. Occurrence of myofibroma involving the jaw bones is common in the younger age groups and represents a unique diagnostic and therapeutic challenge. Differentiating this lesion from other benign and malignant neoplasms is crucial in deciding between a radical and a conservative treatment approach.

Maxillary desmoplastic fibroma with initial symptoms suggestive of sinusitis

Desmoplastic fibroma (DF) is a benign intra-osseous neoplasm characterized by the formation of abundant collagen fibers. It arises most commonly in the jaws and exhibits local aggressiveness and high recurrence rates after local resection. An uncommon case of expansive DF involving the right maxilla, maxillary sinus, and inferior orbital wall of a 49-year-old man whose initial symptoms were similar to acute sinusitis is presented, and the criteria for diagnosis and clinical management are discussed.

Aggressive fibromatosis of the mandible in a two-month old infant

Aggressive fibromatosis is a benign spindle cell tumor with locally infiltrative behavior and tendency to recur. It has overlapping features with other spindle cell lesions and hence it is pertinent to be distinguished from them as they have different treatment modalities. We report a rare case involving the mandible of a two-month old infant with histopathological, immunohistochemical and imaging features.

Solitary myofibroma of the adult mandible: a case report

A 43-year-old woman presented with a swelling in the anterior mandible appearing radiographically as a well-defined radiolucency causing mobility of the anterior teeth. A clinical diagnosis of a radicular cyst led to removal of the lesion and the associated mobile teeth. Postoperative histopathology led to a diagnosis of intraosseous solitary myofibroma of the mandible. Solitary lesions of myofibroma are exceedingly rare in adult jaws, with only 3 previously documented cases.

An unusual myofibroblastic proliferation of the pinna

INTRODUCTION

Myofibrosis of the ear is rare. Myofibromas are mesenchymal tumours which usually present in infancy but have been reported sporadically in adults.

OBJECTIVE

To present a rare case of trauma as a cause of pinnal myofibrosis.

DESIGN AND METHOD

Case report. A 29-year-old soldier suffered repeated trauma from helmet wear and sports, and presented to our clinic with an exquisitely painful lump in the anti-helix of the pinna.

RESULTS

The lump was excised uneventfully. Pathology revealed a reactive myofibroblastic proliferation which, given the history of trauma, raised the possibility of a florid cellular repair process. The main differential diagnosis was myofibroma. Immunohistochemistry was used to exclude other possible causes.

CONCLUSION

No similar case has previously been reported. The aetiology of myofibroma is unclear, but repeated trauma may be a trigger. Histological and immunohistochemical analysis are recommended when the diagnosis is ambivalent.

Oral myofibromas: report of two cases and review of clinical and histopathologic differential diagnosis

Myofibroma is a benign mesenchymal neoplasm composed of myofibroblasts which has been described with different synonyms since the first report in 1951. It may show clinical and histologic features that may be misinterpreted as a malignancy. We describe 2 cases of oral myofibromas affecting infants; the first one showed a rapid growth with teeth displacement and ulceration; the second one presented a relatively slow growth with an indolent course. Differential diagnosis included benign and malignant mesenchymal neoplasms, salivary gland tumors, and reactive processes. Microscopic analysis of both lesions revealed a spindle cell tumor with immunoreactivity for vimentin, muscle-specific actin, and specific smooth muscle isoform alpha-actin, rendering the diagnoses of myofibroma. The patients were treated with surgical excision, and both are in follow-up without any signs of recurrence. Myofibroma presents a wide range of differential diagnosis, including benign and malignant neoplasms. Therefore, accurate diagnosis may avoid an unnecessary aggressive therapy.

[Pediatric mandibular myofibromatosis]

INTRODUCTION

Pediatric myofibromatosis is a rare tumor in neonates and children. Two forms are described, solitary and multicentric, the solitary type is more common and is localized mainly on the head and the neck, mandible involvement is rare. The aim of this article was to report the anatomoclinical and therapeutic features of this pediatric tumor in a case as well as its follow-up.

CASE REPORT

A 10-year-old girl was brought to consultation for a lower left gingival swelling 5 cm in diameter, forming a unit with the mandibular bone. The volume had gradually increased over the last 12 months. Imagery revealed the presence of an osteolytic tumor benign in aspect, but locally aggressive. Conservative surgery was performed. The diagnosis of pediatric myofibromatosis was confirmed. Evolution was excellent and after three years of follow-up, there was no evidence of relapse.

DISCUSSION

Pediatric myofibromatosis often presents as a painless, well-circumscribed, solid nodule. Imagery is very useful to assess lesion extension and for the therapeutic follow-up. The diagnosis is made on anatomopathological findings and immunohistochemical assessment. The treatment of the solitary myofibromatosis is primarily surgical and its prognosis is excellent contrary to the multicentric form.

Clinico-pathologic correlations of myofibroblastic tumors of the oral cavity. II. Myofibroma and myofibromatosis of the oral soft tissues

BACKGROUND

Myofibroma is a solitary benign tumor of myofibroblasts. Myofibromatosis describes multiple, simultaneous myofibromas at different sites in various organs. The clinico-pathologic correlations of myofibroma/myofibromatosis confined only to oral soft tissues were analyzed.

METHODS

In the English language literature, 41 myofibroma and 12 myofibromatosis cases involving the oral soft tissues were found. From our files, three new myofibroma cases were added.

RESULTS

Age at time of diagnosis of oral mucosa myofibroma ranged from birth to 70 years (mean 21.7 years), considerably higher than myofibroma in other parts of the body. Lesions occurred during the first decade (44%) and in the first year of life (17%). Male:female ratio was 1:1.6, contrary to the male predominance in other parts of the body. Common sites were the tongue (32%) and buccal mucosa (18%). Treatment was local excision, either complete (n = 13) or partial (n = 3), wide excision (n = 4), surgery, and chemotherapy (n = 1). Myofibromatosis involving oral soft tissues was diagnosed at birth in nine (75%) patients, within the first year in two, and as a young adult in one. Male:female ratio was 2:1. The tongue was the most common site (50%). Half the patients died of disseminated disease within a few days from birth, three were cured by partial or complete excision, and three experienced spontaneous regression. Histologically, oral mucosa myofibroma/myofibromatosis appearance agreed with findings in the literature.

CONCLUSIONS

Myofibroma should be included in the clinical differential diagnosis of masses of the oral soft tissues, especially in the tongue and buccal mucosa of children and adolescents. Histological differential diagnosis includes benign and malignant spindle-shaped lesions. Treatment of choice is local excision.

Central (intraosseous) myofibroma of the mandible: clinical, radiologic, and histopathologic features of a rare lesion

OBJECTIVE

Myofibroma frequently manifests as a solitary soft tissue tumor and less as simultaneous multiple tumors in both soft tissues and bones. The present study evaluated clinical, radiological, and histopathologic features of myofibroma of the jaws.

STUDY DESIGN

Nineteen cases from the literature and 4 new cases were analyzed.

RESULTS

At initial diagnosis, age ranged from birth to 34 years (mean 7.2 years, median 6 years). Male/female ratio was 2.3:1. Myofibromas were radiolucent solitary lesions located solely in the mandible: 70% unilocular, 30% multilocular; 67% with well-defined borders. Conservative treatment was performed on 75% of the patients; 25% underwent partial jaw resection. Where information was provided, no lesion recurred during 6-month to 17-year follow-up.

CONCLUSION

Although rare, myofibroma of the mandible should be considered in the differential diagnosis of radiolucent lesions (particularly unilocular), especially in children. Treatment of choice is conservative surgery to minimize potential functional and/or esthetic damage.

Myofibromatosis: A case report with a unique clinical presentation

Myofibroma and myofibromatosis have been described under different names since 1951. These lesions are a benign fibroblastic and myofibroblastic proliferation containing a biphasic presentation of spindle-shaped cells surrounding a central zone of less differentiated cells focally arranged in a hemangiopericytoma-like pattern. Classically, these lesions are described in children younger than 2, with two thirds present at birth, and rarely in adults. The typical clinical presentation shows variable growth pattern of a painless purple to pink soft tissue mass, often showing secondary ulceration. Controversy exists as to an autosomal dominant or recessive inheritance versus sporadic occurrence. Presented here is a unique case of myofibromatosis presenting first as a superficial scalp lesion at age 2, followed by other primary lesions of the right mandibular vestibule, right temple, and left mandibular vestibule at ages 9, 12, and 23, respectively. All were treated with excision, without recurrence at the primary site.

Solitary infantile myofibroma compromising the airway

Infantile myofibromatosis is an uncommon and benign condition presenting in the neonatal period. It is self-limiting disease that may present as a localised or generalised process. Various examples of this entity have been reported in the literature. This report describes a neonate with a rapidly growing oropharyngeal lesion obstructing the airway that had the typical histological features of an infantile myofibroma. This case report highlights that a solitary myofibroma may be incredibly extensive making complete excision impossible and can be particularly challenging to manage in terms of airway stabilisation.

Solitary central myofibroma presenting in the gnathic region

Solitary myofibroma of adults is an uncommon neoplasm that typically arises in soft tissue and subcutaneous sites in the head and neck, but rarely within bone. When encountered in the jaws, the lesions exhibit clinical and radiographic features suggestive of an odontogenic tumor or cyst as well as several other neoplastic conditions. Tooth mobility, displacement of teeth, and dramatic jaw expansion may be observed. Analogous to other sites of involvement, gnathic myofibromas are biologically indolent and show little or no recurrence following excision. In rare instances, however, the ability to obtain adequate surgical margins by conservative measures may be limited; thus, issues of local control may supercede the importance of biologic potential. We present the radiologic and histopathologic findings in a case of central myofibroma presenting as a large lytic lesion of the mandible. Myofibroma involving the jaw bones represents a unique diagnostic and therapeutic challenge, and accurate diagnosis and management is predicated on careful correlation of radiographic and pathologic findings.

Solitary adult myofibroma of the mandible simulating an odontogenic cyst

The solitary adult myofibroma is a rare lesion but has a predilection for the head and neck. Intraosseous lesions are common in childhood but uncommon in adults. The lesion is considered to be completely benign but there is the potential for it being confused with more aggressive spindle cell tumours. Histologically it is characterised by two cell types arranged in a biphasic pattern; namely centrally positioned small rounded cells with pale staining nuclei and eosinophilic cytoplasm and peripherally elongated spindle cells. A case is reported of a 34-year-old female patient who presented with a solitary myofibroma in the lower third molar region of the mandible which clinically and radiographically simulated an odontogenic cyst.

Oral spindle cell neoplasms: a review of 307 cases

The infrequent exposure of pathologists to soft tissue spindle cell neoplasms coupled with overlapping histologic patterns can often make diagnosis challenging. We reviewed all nonodontogenic spindle cell neoplasms seen between 1982 and 2002 (86,162 total accessions). Diagnoses were reclassified according to current standards supplemented with immunohistochemistry. Of the 307 neoplasms reviewed (0.36% of total accessions), neural tumors were the most common benign entities, accounting for 21% of total cases. Kaposi's sarcoma was the most common malignancy, accounting for 67% of all cases. Diagnoses were revised for 57 cases. Schwannoma and neurofibroma were most commonly revised to palisaded encapsulated neuroma. There were 8 myofibromas and 1 inflammatory myofibroblastic tumor. There were no oral leiomyomas; that is, all 4 originally reported cases were reclassified as myofibroma, palisaded encapsulated neuroma, and solitary fibrous tumor. With the exception of Kaposi's sarcoma, oral soft tissue sarcomas were rare; most benign lesions were neural in origin. The relatively high prevalence of some tumors, such as myofibroma, likely reflects the use of immunohistochemistry in the diagnosis of spindle cell tumors.

Oral myofibromatosis: an unusual cause of gingival overgrowth

BACKGROUND

This case report describes a rare benign tumour, which presented as discrete areas of gingival hyperplasia affecting both the mandible and the maxilla.

METHOD

Surgical excision of the lesions was carried out under local anaesthetic. Histopathological examination confirmed the diagnosis of oral myofibromatosis.

RESULTS

The condition responded to surgical excision and appears to have limited growth potential. It affects a wide spectrum of ages and can be alarming due to rapid enlargement and ulceration, so careful diagnosis is important to avoid unnecessary aggressive treatment.

Intravascular myopericytoma

BACKGROUND

Myopericytoma is a benign tumor composed of cells that show apparent differentiation towards putative perivascular myoid cells called myopericytes. It arises most commonly in the dermis or subcutaneous tissue of the extremities in adults.

METHODS

We describe a myopericytoma that was unusual in its intravascular location.

RESULTS

A 54-year-old man presented with a 10-year history of a painful slowly growing 1.5-cm nodule in the subcutaneous tissue of the thigh. Histologic examination of the excised lesion showed that is was entirely contained within the lumen of a vein. It was composed of a proliferation of myoid-appearing spindle cells, which were arranged in a striking concentric pattern around numerous blood vessels, in a manner that accentuated the vessel walls. This pattern is characteristic of myopericytoma. In some areas, fascicles of spindle cells, embedded in a myxoid stroma, bulged into the lumina of lesional vessels, reminiscent of myofibroma/myofibromatosis. Lesional spindle cells were diffusely positive for smooth muscle actin, focally positive for CD34 and were negative for desmin, cytokeratin, S100 protein, HMB-45 and CD31.

CONCLUSION

This case illustrates that myopericytoma can be entirely intravascular in its location.

Solitary fibrous tumor in the mental region

Solitary fibrous tumor (SFT) is a rare, benign, soft tissue tumor that most commonly occurs in the pleura; however, it has recently been described in other sites of the body. To date, eight examples of oral SFT have been reported. This paper is a description of the first case of an SFT occurring as a soft tissue tumor in the mental region. Histologically, the tumor was composed predominantly of rather uniform spindle-shaped fibroblastic cells arranged in vague fascicles or in a haphazard fashion, intermingled with abundant collagen fibers. Immunohistochemically, the tumor cells were positive for CD34 and vimentin, and weakly positive for muscle actin and alpha-smooth muscle actin. The diagnosis of SFT may be difficult as this tumor shares a number of histological features with other soft tissue tumors. Awareness of its occurrence in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided.

Sclerosing inflammatory myofibroblastic tumour of the tongue: an immunohistochemical and ultrastructural study

A case of inflammatory myofibroblastic tumour (IMT) arising in the tongue of a 27-year-old man is described. The patient presented with a solitary, well-circumscribed submucosal mass of 4 months duration. The tumour showed in its largest part a paucicellular sclerosing lesion resembling a hyalinizing granuloma surrounded by a thin rim of an admixture of myofibroblasts, plasma cells and foamy histiocytes. Myofibroblasts expressed vimentin and alpha-smooth muscle actin positive immunophenotypes. Ultrastructurally the hyaline areas were composed of abundant collagen fibres with sparse myofibroblasts. Extensive scar-like change in this IMT may be related to a traumatic insult.

Myofibromas presenting in the oral cavity: a series of 9 cases

OBJECTIVES

Solitary myofibromas are well described in the head and neck, but oral examples are less well known, and jaw lesions are rare. We studied the clinicopathologic features of a series of such lesions.

DESIGN

Nine cases of oral myofibromas were retrieved from archives and studied.

RESULTS

Two cases involved the mandible (intraosseous), 3 involved the gingiva, 2 involved the tongue, and 2, the hard palate. There were 4 men and 5 women, aged 9 months to 50 years (mean, 24 years; median, 27 years). Deep lesions showed typical histology, with paucicellular lobules and intervening hemangiopericytoma-like zones. In ulcerated submucosal lesions, these features blended superficially with cellular fascicles. The tumors expressed smooth muscle actin but lacked desmin and S100 protein. None of the tumors recurred or metastasized.

CONCLUSION

Myofibromas appear in osseous, intramuscular, and submucosal aspects of the oral cavity. Ulceration imparts a fascicular appearance that makes superficial biopsy specimens difficult to interpret.

Myofibromas and myofibromatosis of the oral region: A clinicopathologic analysis of 79 cases

The clinicopathologic features of 79 myofibromas or myofibromatoses of the oral and maxillofacial region were studied. The case studies were taken from the files of the Armed Forces Institute of Pathology. The tumors affected 44 males and 33 females (gender was unknown in 2 cases). The patients' ages at diagnosis ranged from birth to 84 years, with mean and median ages of 26.6 and 22 years, respectively. Four patients had infantile myofibromatosis; 2 had extraoral bone lesions and 2 had multiple subcutaneous tumors. In descending order, tumors involved the mandible, tongue, lips, cheek or buccal area, maxilla or palate, pterygomandibular raphae, floor of mouth, and submandibular gland. One third of the tumors affected the bones of the jaws; 12 were central and 15 were cortical or periosteal. All medullary tumors occurred in patients under age 18. On gross examination, the lesions were firm, homogeneous or whorled, white-grey fibrous masses that ranged in size from 0.5 to 5.0 cm. Microscopically, all tumors demonstrated a pattern of nodules or bundles of spindle cells separated by areas of greater cellularity and crescent-shaped vascular spaces. Distinct hemangiopericytoma-like areas were present in 22 cases. Despite apparent circumscription, the tumors commonly infiltrated and entrapped adjacent muscle, nerve, or salivary tissue. Immunohistochemically, 37 of 37 and 39 of 39 tumors stained positively for alpha-smooth muscle actin and muscle-specific actin, respectively, with the former eliciting a more intense reaction. Eight of 8 tumors were weakly positive for CD68, and one case stained focally with S-100 protein. No desmin staining was present in 36 tumors examined. Diagnostic interpretations by the pathologists seeking consultation were malignant or aggressive tumors in 31 cases and other benign conditions in 26. Nine were interpreted as myofibromatosis and 13 offered no interpretation. Thirty-two patients were alive and free of tumor an average of 42 months after initial diagnosis. Four patients had one recurrence each, and 2 had lesions recur twice. Myofibromas are relatively common soft tissue tumors of the maxillofacial region, which have been misinterpreted as malignant or aggressive lesions.

Desmoplastic fibroma of the mandible: report of a case

This paper describes a case of desmoplastic fibroma in a 4-year-old patient with a history of a small slowly growing swelling at the right angle of the mandible over a 3-month period. Desmoplastic fibroma was diagnosed on histological and immunohistochemical bases. The lesion responded well to thorough curettage and has not shown signs of recurrence 3 years after the surgical intervention. The clinical picture, the pathology and the management of the case are described, and the differential diagnosis and treatment are discussed.

Solitary fibrous tumor of the oral cavity: an uncommon location for a ubiquitous neoplasm

Solitary fibrous tumor is an uncommon soft tissue tumor initially reported in the pleura but recently described in other sites of the body. To date, only 5 examples of oral solitary fibrous tumor have been reported. Here, we describe 2 additional cases of this tumor in the oral cavity. The tumors were composed of small to medium-sized spindle cells with bland cytologic features; these cells were haphazardly arranged in highly cellular sheets or ill-formed fascicles as well as in hypocellular areas with hyalinized blood vessels. Both tumors contained blood vessels with a hemangiopericytomalike appearance and expressed vimentin, CD34, and CD99. One case was also strongly positive for bcl-2. The diagnosis of solitary fibrous tumor may be difficult inasmuch as it shares a number of histologic features with other soft tissue tumors. Awareness of its occurrence in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided.

Primary leiomyosarcoma of the mandible in a 7-year-old girl: report of a case and review of the literature

Leiomyosarcoma is a malignant neoplasm of smooth muscle origin that manifests itself uncommonly in the oral cavity because of the paucity of smooth muscle in that location. To the best of our knowledge, only 10 cases of leiomyosarcoma primary to the jawbones have been reported in the English language literature. We report the first pediatric case of leiomyosarcoma arising from the mandible. Facial asymmetry and swelling were accompanied by a rapidly growing exophytic soft tissue mass that caused buccal displacement of the mandibular left permanent first molar. The lesion, observed radiographically as an extensive ill-defined area of osteolytic alveolar destruction, perforated the lingual cortex, displaced the inferior alveolar nerve canal inferiorly, and produced a "floating-in-air" appearance of the first molar. Diagnosis of leiomyosarcoma was made after initial incisional biopsy of the lesion. A 5-cm segmental mandibulectomy and supraomohyoid neck dissection were followed by reconstruction with a dynamic mandibular reconstruction plate and placement of a multidimensional mandibular distraction device in a transport rectangle of bone to promote bifocal distraction osteogenesis. Forty millimeters of distraction (the technical limit of the device) were performed; this was followed by terminal iliac crest bone grafting. Seventeen months after the definitive surgical procedure, the patient remains free of disease.

Myofibromatosis in adults, glomangiopericytoma, and myopericytoma: a spectrum of tumors showing perivascular myoid differentiation

The clinicopathologic features of 24 tumors showing perivascular myoid differentiation are described. These included tumors with histologic features of "infantile-type" myofibromatosis occurring in adult patients (8 cases), tumors with composite features of "hemangiopericytoma" and glomus tumor (9 cases), and tumors with a distinctive concentric perivascular proliferation of spindle cells (7 cases). Evidence of morphologic overlap among these groups suggests they are closely related neoplasms that form a single spectrum. Age of patients with lesions resembling infantile-type myofibromatosis ranged from 23 to 67 years (median, 37 years). Clinicopathologic manifestations of this disease included multicentricity (4 cases), local recurrence (3 cases), persistence of congenital lesions into adulthood (4 cases), and tumors that were multifocal within the confines of one anatomic region (7 cases). Histologically, all cases showed a biphasic pattern that consisted of fascicles of spindle cells with abundant eosinophilic cytoplasm that resembled smooth muscle, in addition to a population of more primitive spindled cells associated with a hemangiopericytomalike vascular pattern. Six cases showed reversal of the typical zonation seen in pediatric cases in that the primitive component surrounded the more mature fascicular areas. Also described are nine tumors with features that are intermediate between glomus tumor and hemangiopericytoma, which we have designated glomangiopericytoma. These tumors are characterized by prominent branching vessels lined by a single row of endothelial cells surrounded by epithelioid cells with a glomoid appearance. In other areas, the tumors showed typical hemangiopericytomatous foci similar to those in the myofibromatosis cases. The principal points of distinction were a lack of myoid nodules and an absence of small primitive cells with basophilic cytoplasm. Ages of these patients ranged from 17 to 78 years (median, 35 years). All tumors were located in the subcutaneous tissue and the superficial soft tissue of the extremities. Recurrence developed in one of six patients with follow-up information. The recurrent tumor had features of angiomatoid malignant fibrous histiocytoma. Finally, we describe a subset of tumors characterized by concentric periluminal proliferation of bland, round to ovoid cells, which we have designated as myopericytoma. Patient age ranged from 10 to 66 years (median, 40 years). All were located in subcutaneous and superficial soft tissue of distal extremities. One patient had two recurrences in 3 years after initial excision. Our study suggests that these three lesional groups comprise a histologic continuum of tumors that share clinical similarities and that, perhaps, are designated more appropriately as perivascular myomas. The relationship of this family of tumors to so-called hemangiopericytoma is discussed.