Oral myofibromas: a report of 13 cases and review of the literature

Mesenchymal neoplasms of the tongue: A clinicopathologic study of 93 cases

Neoplasms of the tongue are relatively common, and the vast majority are epithelial in phenotype. Although uncommon, a diverse and distinctive array of mesenchymal neoplasms arises in this anatomic site. To increase our understanding of these lesions, we reviewed our experience of MNs of the tongue and described their clinicopathologic features. The pathology archives from 2005 to 2021 and the consultation files of one of the authors were queried for all MNs of the tongue. We reviewed the histologic slides and ancillary studies and obtained clinical data from the available medical records. Ninety-three cases were identified, and they form the study cohort - to our knowledge, this is the largest series of mesenchymal neoplasms of the tongue. Forty-eight patients were female, and forty-five were male, with a mean age of 51 years (range: 1-94 years). The tumors included 43 (46.2%) hemangiomas, 14 (15%) granular cell tumors, 8 (9%) lipomas, 4 (4.3%) schwannomas, 4 (4.3%) solitary fibrous tumors - all with low risk of progression based on risk stratification criteria, 2 (2.2%) lymphangiomas, 3 (3.2%) Kaposi sarcomas, 2 (2.2%) chondromas, 2 (2.2%) myofibromas, 1 (1.1%) solitary circumscribed neuroma, 1 (1.1%) perineurioma, 1 (1.1%) neurofibroma, 1 (1.1%) ectomesenchymal chondromyxoid tumor, 1 (1.1%) atypical glomus tumor with a NOTCH2 rearrangement and TLL2 mutation, 1 (1.1%) spindle cell rhabdomyosarcoma, 1 (1.1%) pleomorphic fibroblastic sarcoma, 1 (1.1%) malignant rhabdoid tumor, 1 (1.1%) leiomyosarcoma, 1 (1.1%) angiosarcoma, and 1 (1.1%) alveolar soft part sarcoma. Most of the patients underwent surgical excision, and 1 patient (with hemangioma) underwent embolization. On follow-up, the patient with spindle cell rhabdomyosarcoma developed postoperative numbness at the surgical site and was disease-free through 17 months of follow-up. The patient with leiomyosarcoma declined adjuvant radiation and developed metastasis to the lung at 22 months. The patient with alveolar soft part sarcoma had metastases to the lung at the time of diagnosis and received adjuvant chemotherapy. The remaining patients had no local or distant recurrence. MNs of the tongue are usually benign and characterized by either endothelial, adipocytic, or schwannian differentiation. The mainstay of treatment is surgical excision with the extent of excision determined by tumor type. Adjuvant therapy is reserved for high-grade sarcomas.

Benign connective and soft-tissue neoplasms of the oral and maxillofacial region: Cross-sectional study of 1066 histopathological specimens

BACKGROUND

Benign connective and soft-tissue neoplasms (CSTNs) are unusual in the head and neck region. The aim of the present study was to evaluate the demographic and clinicopathological features of these neoplasms.

METHODS

A cross-sectional study was conducted of cases diagnosed as benign CSTNs, with data collected from biopsy records. The chi-square test was used. A p-value <0.05 was considered indicative of statistical significance.

RESULTS

Among the 38 119 specimens, 1066 (2.79%) were benign CSTNs: 369 fibroblastic/myofibroblastic, 250 adipocytic, 179 vascular, 130 neural, 94 osseous/cartilaginous, 19 muscular, and two fibrohistiocytic. Most patients were female (62.8%) and white-skinned (45.8%). Mean age was 42 years. The tongue (25.2%) was the most affected site for extraosseous neoplasms.

CONCLUSION

This study had the largest sample of benign oral and maxillofacial CSTNs. Although these tumors have similar clinical features, the characterization and differentiation detailed here may help clinicians with regards to the correct diagnosis.

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.

Myofibroma of the gingiva: a rare case report and literature review

Myofibromas are benign uncommon fibroblastic tumors of the soft tissue, bone, or internal organs affecting all ages. These lesions histopathologically may mimic many other soft tissue tumors of the oral cavity such as spindle cell tumors of neurogenic and smooth muscle cell origin, thus leading to misdiagnosis and mistreatment. This case report describes a rare benign tumor, which presented as a soft tissue swelling on posterior gingiva. Surgical excision of the lesion was carried out under local anaesthesia. Histopathologic and immunohistochemical examination confirmed the diagnosis of myofibroma. Myofibroma should be included in the clinical differential diagnosis of masses of the oral soft tissues; however immunohistochemical examination is essential to establish an accurate 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.

Submandibular myofibroma: a case report

PURPOSE

Myofibroma is a rare benign spindle cell neoplasm, and the aim of the present study was to carry out a literature review and present a clinical case of a patient with a myofibroma in the submandibular region and its management.

CONCLUSIONS

Diagnosis of myofibroma can be reached by a histopathologic and immunohistochemical analysis and surgical excision is the treatment of choice.

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.

Myofibroma of the oral mucosa: a case report

OBJECTIVE

To report a case of coexisting irritation fibroma and myofibroma in oral mucosa.

CLINICAL PRESENTATION AND INTERVENTION

One case with two painless, nodular masses, adjacent to each other in the buccal mucosa, was clinically examined with a provisional diagnosis of irritation fibroma, salivary gland tumors, neurofibroma and schwannoma. Histological examination of the smaller swelling showed features of irritation fibroma, while the features of the other mass were compatible with myofibroma or leiomyoma. Additional immunohistochemical examination established the diagnosis of myofibroma.

CONCLUSION

This was a case of a myofibroma that was clinically similar to an adjacent irritation fibroma, which highlights the possibility of misdiagnosis of a myofibroblastic tumor and underlines the importance of histologic examination together with immunohistochemical and/or histochemical analysis if necessary to establish the accurate diagnosis.

Intraosseous infantile myofibroma of the mandible

The myofibroma, especially the intraosseous variety, is an uncommon benign tumor that occurs primarily in children younger than 3 years of age. Since 1966, less than 40 cases of solitary myofibromas of the mandible have been reported in the literature. Myofibroblasts and spindle cells are predominantly found in this benign lesion. These cells are also commonly found in many lesions due to which great difficulty can be encountered in the diagnosis. A rare case of the intraosseous variety of an infantile myofibroma of the mandible diagnosed in a 10-month-old child has been reported. The tumor was completely excised via an intraoral approach and no recurrence has been noted 15 months postoperatively. A brief review of the differential diagnosis of this lesion in terms of its clinicopathologic, histologic, and immunohistochemical features is also discussed.

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.

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.

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 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.

Congenital leiomyomatous epulis: a case report with immunohistochemical study

The histologic and immunohistochemical findings of an extremely rare case of congenital soft tissue mass on the alveolar ridge in an infant are reported. The lesion clinically mimicked an ordinary congenital epulis (congenital granular cell epulis, granular cell tumor of the newborn); however, histologically it consisted of a conglomerate of spindle-shaped cells, akin to smooth muscle cells, which formed interlacing and whorled fasciculi. Nerve fibers with myxoid degeneration, capillaries and muscle walled small vessels intermingled with fasciculi of spindle-shaped cells. The border between the conglomerate of spindle-shaped cells and the surrounding connective tissue was not evident. Immunohistochemically, most of the spindle-shaped cells were intensely positive for antibodies to alpha-smooth muscle actin, HHF-35 and desmin. These findings suggest that the lesion was composed of mature smooth muscle cells that were of hamartomatous or choristomatous nature. The term 'congenital leiomyomatous epulis' is proposed.

Leiomyosarcomas of the oral cavity: an unusual topographic subset easily mistaken for nonmesenchymal tumours

AIMS

Oral leiomyosarcoma is rare and poorly documented. We aimed to characterize these lesions clinicopathologically in order to facilitate their distinction from other spindle cell neoplasms in the oral cavity.

METHODS AND RESULTS

Ten cases of oral leiomyosarcoma were retrieved and studied histologically and immunohistochemically. Clinical data were obtained from referring pathologists and prior literature concerning 46 comparable cases was reviewed. Nine out of 10 cases occurred in adults; 50% arose in the jaws and four showed bone involvement. Histological appearances were similar to leiomyosarcomas elsewhere. In addition to myogenic markers, two cases were also keratin-positive. Four patients developed local recurrence or metastatic disease and three died of tumour (median follow-up 37 months).

CONCLUSIONS

Leiomyosarcoma is under-recognized in the mouth, often being mistaken for a spindle-celled epithelial neoplasm. Aside from an unusual but infrequent tendency to spread to lymph nodes and a location-specific differential diagnosis, its clinicopathological features are comparable to leiomyosarcomas at other locations.

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.

Myofibromas of the oral cavity

Solitary infantile myofibromatosis or myofibroma of the oral cavity is an uncommon condition with only 32 reported cases in the English-language literature. This article presents four additional cases of these solitary myofibroblastic lesions. In addition, the clinical and histologic features of this uncommon spindle cell neoplasm have been reviewed. The similarity in both the clinical and histopathologic features of the "adult" and "infantile" lesions support the proposal that myofibroma is a more accurate and acceptable term for these solitary myofibroblastic lesions of the oral cavity.

Myofibroma of the mandible. Clinicopathologic study and review of the literature

A case of mandibular myofibroma in a 2-month-old boy is presented. Including this case, 24 pediatric and 11 adult patients with maxillofacial myofibroma have been reported since 1981. Of the 24 pediatric patients, 15 (62.5%) had lesions affecting the mandible. The adult cases had no mandibular involvement. Histologic evaluation of the tissue specimen revealed an interlacing pattern of spindle-shaped cells with long oval nuclei. Tissue immunohistochemical staining found it to be reactive for antibodies directed against vimentin and alpha-smooth muscle actin, but not desmin, S-100 protein, neuron-specific enolase, or myoglobin. Electron microscopy examination revealed the following cells: myofibroblast-like cells, fibroblast-like cells, and intermediate cells that were similar to the fibroblast-like cells except for the presence of a few microfilaments. Myoblast-like cells were not seen.