Primary Leiomyosarcoma of the Buccal Mucosa: Report of a Case and Review of the Literature

Epstein-Barr Virus-Associated Smooth Muscle Tumors of Larynx: A Clinicopathologic Study and Comprehensive Literature Review of 12 Cases

Laryngeal mesenchymal neoplasms are rare, with smooth muscle tumors comprising a small subset. Specifically, Epstein-Barr virus (EBV)-associated smooth muscle tumors are exceptionally rare, lacking a comprehensive evaluation of their clinical and histologic features. Two patients (a 59 year old male and 51 year old female) had received renal transplants 156 and 240 months, respectively prior to onset of laryngeal symptoms. Supraglottic polypoid masses were identified and removed conservatively. Histologically, the tumors were hypercellular, showing alternating light and dark areas, the latter composed of primitive appearing round cells, while a more characteristic spindled tumor cell population was noted in the remaining areas. Cytoplasmic vacuoles were noted adjacent to the nucleus. There was no tumor necrosis or pleomorphism, but increased mitotic figures (11-12/2 mm²) were seen, without atypical forms. The tumor cells were strongly immunoreactive with smooth muscle actin and smooth muscle myosin heavy chain and with Epstein-Barr virus encoded RNA (EBER) by in situ hybridization. These patients were reviewed in the context of a thorough English literature review, which demonstrates a wide age range at presentation without a sex predilection, but with most patients from specific ethnic groups (Chinese, Thai, Pilipino). Three-quarters of patients are part of multifocal disease and the majority are post-renal transplantation patients. Conservative management seems to yield the best overall outcome for these indolent tumors. In conclusion, EBV-associated smooth muscle tumors should be considered in any immunocompromised patient with a head and neck smooth muscle tumor, especially when EBER is documented by in situ hybridization. Conservative management may be employed, even when multifocal tumors are documented.

A recurrent leiomyosarcoma of the buccal mucosa: An immunohistochemistry study and literature review

Leiomyosarcoma is a rare type of cancer that affects smooth muscle tissue. Leiomyosarcomas are exceedingly rare in the oral cavity, particularly in the buccal mucosa. The diagnosis is challenging due to non-specific clinical features and significant overlap of morphological findings with several spindle cell tumors. We reported the clinicopathological and immunohistochemical features of a rare recurrent case of leiomyosarcoma in a 73-year-old female presenting clinically as a painful nodule on the posterior right buccal mucosa. Microscopically, the lesion showed atypical spindle cells arranged in a fascicular pattern and frequent mitotic figures. Immunohistochemistry showed strong positivity for vimentin, α-SMA, HHF35, h-caldesmon, and focal positivity for desmin. CD34 highlighted numerous blood vessels distributed throughout all tumor stroma. S-100 protein, myogenin, and pan-cytokeratin (AE1/AE3) were negative. Surgical excision followed by chemotherapy was carried out, and no recurrence was observed after 1 year of follow-up. Careful histopathological and immunohistochemistry analysis of these lesions is essential to ensure a correct diagnosis. Early surgical excision with tumor-free margins and prolonged follow-up is strongly recommended.