Radiographical bony lesions after discontinuation of immunosuppressant therapy: bone involvement in sarcoidosis

Abstract

We describe a patient who had failed renal transplant after 13 years, eventually requiring a graft nephrectomy and discontinuation of immunosuppressive therapy, including antithymocyte globulin, tacrolimus and mycophenolate while on steroid avoidance protocol. Within a few months of complete discontinuation of the immunosuppressive medications, she developed lower back pain associated with numbness in her right anterolateral thigh. The radiological imaging demonstrated multiple bony lesions throughout her axial and appendicular skeleton with normal pulmonary findings. A computerised tomography-guided bone biopsy from the left iliac crest revealed fragments of bone with granulomatous inflammation, thus making the diagnosis of extrapulmonary sarcoidosis. Initiating treatment with prednisone resulted in near-complete resolution of symptoms. Long-term immunosuppressive therapy is administered to all renal transplant recipients to help prevent acute rejection and loss of renal allograft. This case highlights that immunosuppressants can conceal the presence of underlying conditions in transplant patients.

Keywords: General practice / family medicine; Radiology; Rheumatology.

Figure 1

MRI denoting lesions of the lumbar spine.

Figure 2

PET scan, non-lytic multifocal intensely hypermetabolic bone lesions throughout the axial and proximal appendicular skeleton.

Figure 3

PET scan after initiation of prednisone, 3 months later. Complete resolution of all tracer-avid osseous uptake.

Figure 4

Histopathologic section: negative for malignancy.