Poster Presentation Annual Meetings of the Endocrine Society of Australia and Society for Reproductive Biology and Australia and New Zealand Bone and Mineral Society 2016

Oral lesions in an immunosuppressed patient on antiresorptive therapy for osteoporosis: a diagnostic conundrum (#342)

Julia Shrosbree 1 , Ann McCormack 1 , Jackie Center 1 , John Eisman 1
  1. Department of Endocrinology and Diabetes , St Vincent's Hospital, Sydney , NSW, Australia

A 36-year-old female, immunosuppressed in the context of a prior cardiac transplant in 2010 had a concurrent 3 year history of steroid-induced osteoporosis for which she had received anti-resorptive therapy (risedronate followed by denosumab). She presented with multiple areas of exposed bone in the mouth at both the site of a recent tooth extraction and in multiple regions distant from the site of dental intervention. She also had numerous oral ulcerative lesions of the gums. Given her background of anti-resorptive therapy for osteoporosis, the presumptive primary diagnosis was of medication-related osteonecrosis of the jaw (MRONJ).

However, there were several features in this case that were unusual for MRONJ. These included regions of exposed bone distant from prior extraction site, which occurred spontaneously, lesions on both the maxilla and mandible, normal radiologic imaging and multiple oral ulcerative lesions raising the possibility of a more systemic disorder. The constellation of these features, which were not classic for MRONJ, prompted the decision to biopsy these lesions to exclude other diagnoses including malignancy. Biopsy demonstrated Epstein Barr-Virus–related post-transplant lymphoproliferative disorder.

PET scanning demonstrated additional sites of disease in the adenoids and distal right triceps muscle.   The correct diagnosis enabled early definitive treatment of the lymphoproliferative disorder with rituximab. This led to resolution of the bone and mucosal lesions and rapidly decreased oral pain. Furthermore, exclusion of MRONJ as a differential diagnosis allowed continuation of denosumab to manage steroid induced osteoporosis.  

The role of biopsy in diagnosis of MRONJ is controversial due to the risk of disease progression. This case highlights the need to weigh this risk against the prognostic implications of a delayed diagnosis of malignancy. Hence diagnostic biopsy should be considered in cases with atypical features of MRONJ particularly in patients with underlying immunosuppression.