SAPHO syndrome presenting as widespread bony metastatic disease of unknown origin

Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis (SAPHO) Syndrome Mimicking Bone Metastases in the Spine: A Presentation of Two Cases and Literature Review

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome is a rare disorder of unknown etiology with heterogeneous clinical manifestations. We describe two cases of patients diagnosed with SAPHO syndrome mimicking spinal bone metastases. A literature review was conducted to identify similar previously reported cases. The first patient was a 56-year-old woman with progressive back pain for six months who was referred to the neurosurgery department for suspected spinal metastases. A spinal CT scan revealed hyperdense lesions at T10 and hyperdense changes in the lumbar vertebrae. Spinal MRI demonstrated bone marrow edema that was hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging in multiple thoracic vertebrae, and the PET/CT showed multiple skeletal lesions affecting the spine with low-to-moderate 18F-FDG uptake. Scintigraphy showed the characteristic "bull's head" sign with increased uptake in the manubrium and bilateral sternoclavicular joints. The second patient was a 66-year-old woman with a four-month history of back pain, who was admitted with multiple spinal lesions. The diagnosis was made after bone scintigraphy demonstrated the characteristic findings of the syndrome. Both patients lacked cutaneous lesions on presentation but reported previous skin lesions. SAPHO syndrome is a rare condition, and bone lesions associated with the disease may be misdiagnosed as bone metastases. Knowledge of the syndrome and its imaging findings is essential for accurate diagnosis and treatment.

SAPHO syndrome with a purely osteolytic form: A case report

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome is a rare, chronic autoinflammatory disorder that can present with a constellation of cutaneous and osteoarticular symptoms. Osteodestructive lesions are not pathognomonic, whereas hyperostosis and osteitis are the most prominent imaging findings. We report the case of a man with osteolytic changes of the lumbar vertebra and a history of palmoplantar pustulosis. Biopsy revealed no neoplasm, suggesting SAPHO syndrome. Our case demonstrates that knowledge of atypical radiologic findings is necessary for the diagnosis of SAPHO syndrome.

Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis Syndrome with Purely Osteolytic, Not Osteosclerotic, Lesions Mimicking a Malignant Tumor

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare inflammatory disorder with multiple phenotypes. The syndrome has identifiable radiologic characteristics that are the most important when making a diagnosis. X-rays of cases diagnosed with SAPHO syndrome reveal sclerotic lesions or mixed lytic and sclerotic lesions. Pure osteolytic lesions in SAPHO syndrome are rare, and to the best of our knowledge, no study has reported the radiologic change of purely osteolytic lesions to osteosclerotic lesions over time. Herein, we report on the case of a woman experiencing severe left thigh acute pain and having a medical history of palmoplantar pustulosis. Although SAPHO syndrome was suspected because of palmoplantar pustulosis, based on radiologic findings, bone metastasis of a malignant tumor or chronic bacterial osteomyelitis owing to a purely osteolytic lesion was suspected. However, needle biopsy revealed no malignancy and bacterial culture was negative, thus suggesting SAPHO syndrome. Nonsteroidal anti-inflammatory drugs, bisphosphonates, and corticosteroids were administered, which improved the left thigh pain. Furthermore, the radiologic change of osteolytic lesions to osteosclerotic lesions over time was confirmed, leading to the diagnosis of SAPHO syndrome. Our case demonstrates that knowledge of atypical radiologic findings is necessary to diagnose initial SAPHO syndrome.

Syndromes with chronic non-bacterial osteomyelitis in the spine

Chronic non-bacterial osteomyelitis (CNO) has been known for over of 40 years. It is an underrecognized entity due to the low number of described cases and poor propagation awareness of the problem. Chronic non-bacterial osteomyelitis is usually confused with infectious spondylodiscitis or malignant lesions, both primary and metastatic. Failing to consider CNO as one of possible lesions of the spine among an array of differential diagnoses may lead to a prolonged ineffective treatment increasing treatment-related morbidity. In this paper the authors describe these two syndromes, with a possible autoimmune background – chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO syndrome – that include CNO being among the manifestations. The authors present the spinal symptomatology of CNO for both syndromes published so far to help spine clinicians organize the information for better usage in everyday clinical practice.

The SAPHO syndrome revisited with an emphasis on spinal manifestations

The synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome includes a group of chronic, relapsing, inflammatory musculoskeletal disorders with similar manifestations, in particular synovitis, hyperostosis, and osteitis, which may or may not be associated with neutrophilic skin eruptions such as palmoplantar pustulosis and acne conglobata. The syndrome occurs at any age, can involve any skeletal site, and its imaging appearances are variable, depending on the stage/age of the lesion and imaging method. The diagnosis is difficult if there is no skin disease. Awareness of the imaging appearances, especially in the spine, may help the radiologist in avoiding misdiagnosis (e.g., infection, tumor) and unnecessary invasive procedures, while facilitating early diagnosis and selection of an effective treatment. In this article, we provide an overview of the radiological appearances of SAPHO syndrome, focusing on the magnetic resonance imaging findings of vertebral involvement, and present relevant clinical and pathological features that assist early diagnosis.

The SAPHO syndrome: a single-center study of 41 adult patients

OBJECTIVE

The SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis) is a rare disease and only a few series have been published about it. We describe the experience of a rheumatology department with a focus on the therapeutic aspects.

METHODS

All cases of SAPHO fulfilling the Benhamou criteria and seen between 1992 and 2013 in our unit were retrospectively included.

RESULTS

Forty-one patients (11 men and 30 women) were included. The average age was 45 years (20-80 yrs) at the time of diagnosis. Nineteen patients had palmoplantar pustulosis, 3 had psoriasis vulgaris, 3 had severe acne, and 15 had no dermatological involvement. Bone symptoms involved mainly the anterior chest wall (n = 28, 68%), followed by the spine (n = 16, 39%) and sacroiliac joints (n = 12, 29%). Four patients had peripheral osteitis and 2 had mandibular osteitis. Ten patients had peripheral arthritis affecting mainly the knees and wrists. None of the 36 patients tested was HLA-B27-positive. At least a partial response was achieved with colchicine, methotrexate, or sulfasalazine in 0/6, 2/4, and 1/6 of patients, respectively. Antibiotic therapy (azithromycin, n = 7; doxycycline, n = 2) was effective in 2/9 patients. Pamidronate was prescribed in 26 patients with bone involvement and 18/22 patients evaluable at 6 months responded to this therapy. Two patients were treated with tumor necrosis factor blockers: 1 with infliximab and 1 with adalimumab, followed by etanercept.

CONCLUSION

Based on our experience, SAPHO can be diagnosed in the elderly. It was not associated with HLA-B27. Soft tissue involvement was common and the bisphosphonates were generally effective on bone involvement.

SAPHO syndrome

SAPHO syndrome is a disorder characterized by Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis. As the osteoarticular and skin manifestations often do not occur simultaneously and there are no validated diagnostic criteria, the diagnosis can be difficult. Clinical and imaging investigation is necessary to establish the many differential diagnoses of SAPHO syndrome. The etiopathogenesis involves infectious (probably Propionibacterium acnes), immunologic, and genetic factors. Treatment is based on information gathered from case reports and small series, and is related to specific skin or articular symptoms.