Breast cancer recurrence in the mandibular condyle causing jaw pain

What happened, in summary

A 56-year-old woman had been treated for grade 1 invasive ductal carcinoma of the right breast in 2010 with lumpectomy, right axillary clearance, chemotherapy, and radiation. She then took tamoxifen through 2015 and continued annual mammographic surveillance after discharge from oncology follow-up. Her June 2019 scan showed no local breast recurrence.

Several months later, she developed progressive pain near the right ear and jaw that worsened with chewing. Examination was largely normal, and the symptoms initially resembled temporomandibular-joint dysfunction or pain from a longstanding salivary-gland stone. Imaging identified a lesion in the right mandibular condyle. Fine-needle cytology initially suggested ameloblastoma, but an open biopsy confirmed metastatic breast cancer that was ER-positive, PR-positive, and HER2-negative. Repeat MRI then showed progression beyond the condyle into the masticator space near the auditory canal.

Because complete surgical removal would have been highly morbid, the multidisciplinary team recommended palliative treatment. She received anastrozole before radiation to reduce the tumor burden, then completed 60 Gy in 20 fractions to the right temporomandibular-joint region in August 2020. By November, she reported less pain, better mouth opening, and improved jaw function, with some discomfort during side-to-side movement. She remained on anastrozole, and palbociclib was planned as the next step in her ongoing metastatic breast cancer care.