Myofibroblastic lesions in the oral cavity: Immunohistochemical and ultrastructural analysis

Recurrent Nodular Fasciitis of the Oral Mucosa: Case Report and Review of the Literature

Among all benign and reactive mesenchymal lesions, nodular fasciitis is most frequently misdiagnosed as a sarcoma due to its concerning clinical and histopathological features: it arises on fascial surfaces, grows rapidly, and may infiltrate into adjacent tissues and blood vessels. The most commonly involved sites include upper extremities, trunk, head, and neck, with rare occurrences in the oral cavity. Recurrences following both incomplete and complete excision are rare, and its natural history progresses through self-limited growth followed by spontaneous regression. Herein we present a rapidly growing nodular fasciitis of the buccal mucosa confirmed by molecular testing for USP6 gene rearrangements which recurred 3 weeks following complete surgical excision. Additionally, we review reports of oral cavity nodular fasciitis between 2011 and 2023. Increasing awareness and diagnostic accuracy of this benign mimicker of oral cavity malignancy will help prevent unnecessary radical surgical resections.

Incidental Solitary Myofibroma in a Young Adult Female Patient: A Case Report and Comprehensive Literature Review of Myofibroma in Adults

Myofibroma is a rare mesenchymal tumor typically observed in children, with only a few reported cases in adults. It can be easily mistaken for more common benign lesions, making it essential to include them in the differential diagnosis of soft tissue masses. This case report presents a rare instance of myofibroma in a young adult, and a comprehensive review of the literature presenting case reports and case series of myofibroma cases in the head and neck regions of adult patients aged > 18 years. A 22-year-old woman presented with a gradually enlarging, painless mass on the right side of her neck which had been developing over the course of two years. An ultrasound initially identified a 1×2 cm lipoma; however, during surgery, a fibrous soft tissue mass was discovered extending beneath the sternocleidomastoid muscle. The mass was found to be closely associated with the posterior auricular nerve. Despite its proximity to the nerve, the tumor was successfully excised, while preserving the nerve. Histopathological analysis confirmed a diagnosis of myofibroma. This case highlights the rare occurrence of myofibromas in adults and emphasizes the importance of considering this diagnosis when evaluating soft-tissue masses. Even when imaging suggests a benign lesion, surgical intervention may yield unexpected results. Accurate diagnosis through histopathology is essential, and careful surgical techniques, including nerve preservation, play a critical role in successful management. Long-term follow-up is necessary to ensure the absence of tumor recurrence.

Intraosseous myofibroma mimicking an odontogenic lesion: case report, literature review, and differential diagnosis

BACKGROUND

Intraosseous myofibroma of the jaw is a rare neoplasm of mesenchymal origin with limited comprehensive understanding. It typically affects patients in the first two decades of life with a male predilection.

CASE PRESENTATION

This study presents a rare case of myofibroma mimicking an odontogenic lesion in a 2-year-old boy. The patient presented with an incidental finding of a painless swelling of the right mandibular ramus of unknown etiology. Imaging analysis revealed a solid, expansile lesion adjacent to the germinal zone of the right mandibular first molar. Histopathologic analysis and immunohistochemistry after incisional biopsy suggested a possible central odontogenic fibroma, and the patient underwent total enucleation, leading to the final diagnosis of intraosseous myofibroma. Follow-up examinations showed no evidence of recurrence.

CONCLUSIONS

This report contributes to the understanding of myofibroma in pediatric patients and underscores the critical role of meticulous histopathologic examination for effective surgical planning and optimal patient outcomes.

Ultrastructural and immunohistochemical evaluation of hyperplastic soft tissues surrounding dental implants in fibular jaws

In reconstructive surgery, complications post-fibula free flap (FFF) reconstruction, notably peri-implant hyperplasia, are significant yet understudied. This study analyzed peri-implant hyperplastic tissue surrounding FFF, alongside peri-implantitis and foreign body granulation (FBG) tissues from patients treated at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Using light microscopy, pseudoepitheliomatous hyperplasia, anucleate and pyknotic prickle cells, and excessive collagen deposition were observed in FFF hyperplastic tissue. Ultrastructural analyses revealed abnormal structures, including hemidesmosome dilation, bacterial invasion, and endoplasmic reticulum (ER) swelling. In immunohistochemical analysis, unfolded protein-response markers ATF6, PERK, XBP1, inflammatory marker NFκB, necroptosis marker MLKL, apoptosis marker GADD153, autophagy marker LC3, epithelial-mesenchymal transition, and angiogenesis markers were expressed variably in hyperplastic tissue surrounding FFF implants, peri-implantitis, and FBG tissues. NFκB expression was higher in peri-implantitis and FBG tissues compared to hyperplastic tissue surrounding FFF implants. PERK expression exceeded XBP1 significantly in FFF hyperplastic tissue, while expression levels of PERK, XBP1, and ATF6 were not significantly different in peri-implantitis and FBG tissues. These findings provide valuable insights into the interconnected roles of ER stress, necroptosis, apoptosis, and angiogenesis in the pathogenesis of oral pathologies, offering a foundation for innovative strategies in dental implant rehabilitation management and prevention.

Evaluation of stromal myofibroblasts in oral submucous fibrosis and its malignant transformation: An immunohistochemical study

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion, with oral squamous cell carcinoma (OSCC) being the most prevalent malignancy affecting the oral mucosa. The malignant transformation of OSF into OSCC is estimated to occur in 7-13% of cases. Myofibroblasts (MFs) play pivotal roles in both physiological and pathological processes, such as wound healing and tumorigenesis, respectively. This study aimed to explore the involvement of MFs in the progression of OSF and its malignant transformation.

MATERIALS AND METHODS

In total, 94 formalin-fixed paraffin-embedded tissue blocks were collected, including normal oral mucosa (NOM; n = 10), early-moderate OSF (EMOSF; n = 29), advanced OSF (AOSF; n = 29), paracancerous OSF (POSF; n = 21), and OSCC (n = 5) samples. Alpha-smooth muscle actin was used for the immunohistochemical identification of MFs.

RESULTS

NOM exhibited infrequent expression of MFs. A higher staining index of MFs was found in AOSF, followed by EMOSF and NOM. Additionally, a significant increase in the staining index of MFs was found from EMOSF to POSF and OSCC. The staining index of MFs in NOM, EMOSF, AOSF, POSF, and OSCC was 0.14 ± 0.2, 1.69 ± 1.4, 2.47 ± 1.2, 3.57 ± 2.6, and 8.86 ± 1.4, respectively. All results were statistically significant (P < 0.05).

CONCLUSIONS

The expression of MFs exhibited a gradual increase as the disease progressed from mild to malignant transformation, indicating the contributory role of MFs in the fibrogenesis and potential tumorigenesis associated with OSF.

A multicentric case study of fibroblastic and myofibroblastic oral spindle cell lesions

Context

Spindle cell lesions comprise a vast plethora of benign and malignant lesions with similar clinical and radiographic features. Their overlapping histopathologic features ensure a diagnostic dilemma.

Aim

The current multicentric study aims to delineate fibroblastic and myofibroblastic oral spindle cell lesions based on cytomorphology and comprehensive immunohistochemical analysis.

Settings and Design

The experimental study was conducted at MS Ramaiah University of Applied Sciences, Bangalore, and All India Institute of Applied Sciences, Delhi.

Methods and Material

A comprehensive histological scoring criteria and panel of immunohistochemical makers (STAT6, CD31, CD34, S100, SMA, vimentin, pan-CK, HHF-35, Ki67, ALK, desmin, HMB-45, SATB2, ERG, EMA and CD99) were employed concurrently for the first time for fibroblastic and myofibroblastic oral spindle cell lesions. The data obtained was tabulated and studied.

Statistical Analysis Used

NA. Results: Using cytological scoring criteria and panel of immunohistochemical makers, the cases analysed and characterized were desmoplastic fibroma, fibrosarcoma, leiomyosarcoma, nodular fasciitis, neurofibroma and epithelioid inflammatory myofibroblastic sarcoma (EIMS).

Conclusions

The diagnostic strategies need to be upgraded for the diagnosis of spindle cell lesions. Emphasis must be placed on cytomorphology, an immunohistochemistry (IHC) panel of markers is imperative for the accurate diagnosis of fibroblastic and myofibroblastic oral spindle cell lesions.

Leiomyoma and Leiomyosarcoma (Primary and Metastatic) of the Oral and Maxillofacial Region: A Clinicopathological and Immunohistochemical Study of 27 Cases

Smooth muscle neoplasms represent an important group of lesions which is rare in the oral cavity. Leiomyoma (LM) is benign smooth muscle/pericytic tumor usually presenting as non-aggressive neoplasm, while leiomyosarcoma (LMS) represents its malignant counterpart. The rarity of these lesions, together with its unspecific clinical presentation and a variable histopathological appearance, lead to a broad list of differential diagnoses, hampering their diagnoses. Therefore, in this study we describe the clinical and microscopic features of a series of oral and maxillofacial LMs and LMSs. A retrospective search from 2000 to 2019 was performed and all cases diagnosed as LM and LMS affecting the oral cavity and gnathic bones were retrieved. Clinical and demographic data were obtained from the patients' pathology records, while microscopic features and immunohistochemistry were reviewed and completed when necessary to confirm the diagnoses. Twenty-two LMs and five LMSs were obtained. In the LM group, males predominated, with a mean age of 45.7 years. The upper lip was the most affected site, and 18 cases were classified as angioleiomyomas and four as solid LM. In the LMS group, females predominated, with a mean age of 47.6 years. The mandible was the most affected site. Diffuse proliferation of spindle cells, with necrosis and mitotic figures, were frequent microscopic findings. LMs and LMSs were positive for α-smooth muscle actin, HHF-35 and h-caldesmon. In conclusion, oral LM/LMS are uncommon neoplasms with the latter usually presenting as metastatic disease. H&E evaluation may be very suggestive of oral LMs, but h-caldesmon staining is strongly recommended to confirm LMS diagnosis.

Oral myofibroma presenting as an aggressive gingival lesion

Myofibromas are benign neoplasms of myofibroblastic origin and rarely encountered in the oral cavity. Myofibroma may frequently grow rapidly leading to suspicion of malignancy. This may lead to a tendency for aggressive management. The histopathology of this tumour has similarity with other spindle cell tumours and often requires immunohistochemical staining for diagnosis. Here, we present a case of myofibroma in a 15-year-old female patient who reported with an aggressive gingival swelling and discuss the various histopathological differential diagnosis.

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.

High-grade myofibroblastic sarcoma of the pleura: A case report and literature review

High‐grade myofibroblastic sarcoma (HGMS) is a rare cancer that has high recurrence and metastatic rates. Here, we report the first case of HGMS originating from the pleura. Based on the findings of pleural biopsy, pathological examination and immunohistochemical staining, grade III myofibroblastic sarcoma (MS) was diagnosed. The patient underwent eight cycles of chemotherapy (epirubicin and ifosfamide), followed by radiotherapy. As of May 2020, the patient had been followed for six months and no tumor progression had occurred.

Key points

This is the first report of high‐grade myofibroblastic sarcoma originating from the pleura. The patient was treated via nonsurgical strategies, including chemotherapy and radiotherapy.

Aggressive Intraosseous Myofibroma of the Maxilla: Report of a Rare Case and Literature Review

Myofibroma (MF) is a benign mesenchymal myofibroblast-derived tumor, which occurs most frequently in children, and rarely affects the maxilla. We reported a case of an aggressive intraosseous lesion found in the maxilla of a 9-year-old female child. Intraorally, the swelling extended from tooth 12 to 16, causing displacement of teeth 13, 14, and 15. Computed tomography revealed a large osteolytic lesion causing thinning and cortical erosion. Microscopically, the lesion showed a proliferation of spindle-shaped cells, with elongated nuclei and eosinophilic cytoplasm, arranged in interlaced fascicles. The immunohistochemical analysis revealed cytoplasmic positivity for α-SMA and HHF-35, and negativity for desmin, laminin, S-100, β-catenin, and CD34. Ki-67 was positive in 8% of tumor cells. The diagnosis was MF. Herein, we describe an additional case of central MF arising in the maxilla, including clinical, imaging, microscopical, and immunohistochemical features, as well as a review of the literature.