Male patient, aged 37 years, who came to the clinic with a right paramandibular nodule, 6 years old, which has increased in size in the last year. He reported that the lesion appeared after the exodontia of a lower molar.46
On examination, the patient presented a nodule 1.5 cm in diameter, at the bottom of the vestibule, at the level of 45 and theoretical 46. The lesion was mobile, well demarcated, elastic in consistency and painful on palpation. The overlying mucosa was normal. An orthopantomography was performed and no mandibular pathology was observed. Resection of the lesion was performed under local anaesthesia, previously locating the exit of the mentonian nerve to preserve it.1

Macroscopically, the lesion was a well-demarcated, whitish, nodular lesion measuring 2 x 1.5 x 1 cm in size. Microscopically the lesion consisted of uniform spindle-shaped cells with poorly defined cytoplasmic boundaries, oval or round nuclei, without mitosis or nuclear pleomorphism. The cells were randomly arranged interspersed with collagen fibres and isolated blood vessels. There were no areas of necrosis, no haemangiopericytoid pattern. At the periphery the lesion was delimited by a connective tissue border.

Immunohistochemically the lesion cells were: strongly positive for: vimentin, CD34 and bcl2 ; weakly positive for: factor XIIIa and muscle specific actin (1A4); and negative for: S-100 protein, cytokeratins (CAM 5,2;AE1-3), desmin and muscle actin (HHF35).

The postoperative course was uneventful, and one year after surgery there are no signs of local or regional recurrence.