Heterotopic ossification is the formation of new bone outside of the skeleton. We describe a previously unreported case of heterotopic ossification occurring within a fasciocutaneous radial forearm free flap for reconstruction following tongue squamous cell carcinoma resection. Although this is a benign condition, it is important to consider and exclude a neoplastic recurrence.
Heterotopic ossification is the formation of new bone outside of the skeleton. Although no reported cases within fasciocutaneous radial forearm free flaps have been noted, there are reported cases within other tissue locations, including the vascular pedicle of fibula free flap reconstructions, small bowel mesentery, and also within a temporalis fascial flap pedicle.
A 71-year-old man was referred by his general medical practitioner with a non-healing ulcer on the lateral tongue of 8-week duration. Clinically a 3-cm × 2-cm non-tender, indurated ulcer was noted on the right mid-posterior lateral tongue, extending onto the lingual mucosa of the mandible. An incisional biopsy confirmed a squamous cell carcinoma, which on imaging represented a T2, N0, and M0 stage 2 tumour.
Following agreement at the Head and Neck Multidisciplinary Team meeting, the patient underwent tongue squamous cell carcinoma resection, ipsilateral level I–IV selective neck dissection, and reconstruction with a fasciocutaneous radial forearm free flap harvested from the left arm. The surgical procedure was uneventful and the patient was discharged 8 days postoperatively.
At 3-month review, the patient described firmness in his tongue and altered speech. Clinical examination revealed a 2-cm firm mass within the body of the tongue flap reconstruction. An orthopantomogram confirmed a radiopacity, and an incisional biopsy reported “small dissociated fragments of connective tissue including bone which could represent a metaplastic process”. A computerized tomogram (CT) scan was requested, which showed an opacification within the bulk of the free flap ( Fig. 1 ).
The patient was taken to theatre and the pathological entity was excised. Clinically it appeared to be bony-hard, and histologically it was reported as “an area of soft tissue ossification with bone marrow formation” ( Fig. 2 ). The bone was of woven type and rimmed by osteoblasts with no histological evidence of neoplasia.