Low-grade myofibroblastic sarcoma was recently described as representing a malignant mesenchymal tumour showing myofibroblastic differentiation.
It can occur at any age with a slight male predominance. About 20 cases have been reported in the oral cavity, especially in the tongue and bone,1
while gingiva as the primary site has been described only once so far.2
A painless, slow-growing mass with a relatively indolent course is the most common clinical presentation,1 3
and the frequent absence of a detectable epithelial discontinuity raises the risk of delay in diagnosis and subsequent worsening prognosis.
The correct diagnosis of myofibroblastic sarcomas can be challenging. At the clinical examination, the tumour mass can be associated with a persisting ulceration as in the present case, but cases have been reported in the literature where the overlying mucosal surface appeared normal in colour and texture.4
Sometimes, diagnostic orientation can be confused by the anatomic location as in the present case, where an accumulation of plaque as a consequence of a poor oral hygiene might initially resemble common inflammatory periodontal disease.
The presence of an osteolytic and bone-destructive activity at Rx examination can address the diagnosis,4
although in our patient, where the tumour mass was so close to the bone, no bone involvement was demonstrated at the Rx examination.
A definitive diagnosis requires histopathological and immunohistochemical analyses.4
An incisional biopsy must be performed, reaching an adequate submucosal depth, because a misinterpretation can result from the specimen being sampled from the tumour surface, which contains mainly the granulation tissue-like and hypocellular areas but not the atypia hypercellular areas.5
Fine-needle aspiration biopsy might be non-contributory.6
Due to its rarity, the biological behaviour and the treatment of choice are still unclear. Aggressive surgical resection with wide margins and, occasionally, radiotherapy have been advocated. Although myofibrosarcomas generally behave as low-grade malignant sarcomas, sometimes they can exhibit an aggressive pattern with local recurrence, while distant metastases have been rarely reported.2 3 7
Consistent with the case reported here, evolving techniques of surgical reconstruction may allow more of these tumours to be completely resected, with less patient morbidity.8
- Low-grade myofibroblastic sarcoma is an uncommon malignant neoplasm of the oral cavity.
- Diagnosis of low-grade myofibroblastic sarcoma can be challenging.
- Early detection of oral malignancies is based on histological examination of any suspect lesion.