Age / Sex : 35 / M

Chief complaint :

Discussion

Answer:  SAPHO

Findings:

B clavicle AP :  Hyperostosis & sclerosis  in both  anterior costochondral junction of 1st rib

MRI: Focal bone marrow edema in clavicular medial end, 1^st costosternal junction, and Rt lower sternum (Rt 5th-7th costosternal junction) with high SI on STIR and low signal on T1WI & irregular enhancement

Differential Diagnosis:

Tietze syndrome,  nonspecific multifocal infection

Diagnosis:  

SAPHO  (Synovitis,  Acne, Pustulosis, Hyperostosis, & Osteitis) Syndrome

Discussion:

SAPHO syndrome is an inflammatory clinical condition with aseptic bone lesions and characteristic skin manifestations if present as severe acne and/or pustulosis of palms and soles. The skin lesions may occur before, simultaneously, or after the onset of skeletal symptoms. 

Osteoarticular manifestations include synovitis, hyperostosis, osteitis, arthropahty, and enthesopathy. The anterior chest wall involvement is the most common site of involvement in adult. In the early stage, it can be evident as soft tissue swelling around the costoclavicular ligaments. However, in the late stage, hyperostosis, osteosclerosis, and hypertrophy of the medial ends of clavicles are evident. These lesions characteristically show hot uptake on bone scintigraphy and may resemble the contours of bull’s head. Diagnostic criteria for SAPHO  have not been validated but after excluding an infective cause, palmo-plantar keratodermia, diffuse idiopathic skeletal hyperostosis, and retinoid therapy, the presence of only one of the four inclusion criteria is sufficient for the diagnosis of SAPHO.

References:

1. Depasquale R, Kumar N, Lalam RK, Tins BJ, Tyrrell PN, Singh J, et al. SAPHO: what radiologists should know. Clin Radiol 2012;67:195-206


2. Earwaker JW, Cotten A. SAPHO: syndrome or concept? Imaging findings. Skeletal Radiol 2003;32:311-327


3. Fu Z, Liu M, Li Z, Fan Y, Zhang J, Zhang X, et al. Is the bullhead sign on bone scintigraphy really common in the patient with SAPHO syndrome? A single-center study of a 16 year experience. Nucl Med Commun 2016;37:387-3