(9) Upsala J Med Sci 111 (2): 243–248, 2006 SAPHO Syndrome with a Tumour-like Bony Proliferative Lesion in Distal Femur. A Case Report Munenori Watanuki, Masahito Hatori and Shoichi Kokubun Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan ABSTRACT SAPHO syndrome is a group of bone and joint abnormalities associated with skin lesions. A 29-year-old male presented with severe acne on his trunk and anterior chest wall, right knee and foot pain. Radiographs and magnetic resonance images showed hyperostosis in the sternocostoclavicular region, sclerosis of one-third of the right distal 5th metatarsal bone and bony outgrowth from the medial condyle of the right femur .The histological findings of the biopsy specimen were consistent with those of old osteomyelitis. All fungal and microbacterial cultures were negati- ve. Pain and swelling of the right knee and foot repeated remission and aggravation. There were no radiological changes of the above-mentioned lesions noted within 4- years follow-up. INTRODUCTION In 1987, Chamot et al. proposed the term, SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome, to designate collectively bone and joint abnor- malities associated with skin lesions [1, 2]. The common site of skeletal lesions in SAPHO is the chest wall (clavicle, sternum, and sternoclavicular joints). Long bones are occasionally involved. Radiographic changes of the long bone lesions generally suggest either infectious osteomyelitis or a neoplasm such as Ewing’s sar- coma[3]. We report a case of SAPHO syndrome having a cauliflower-like bony mass in the left femur together with an anterior chest lesion and sclerosis of the left 5th metatarsal bone. To the best of our knowledge, no cauliflower-like bone protru- sion as in the present case has been reported. 243 Received 7 June 2005 Accepted 15 June 2005 CASE REPORT A 29-year-old male had severe acne on his trunk in the summer, in 1991. He had anterior chest pain in October 1999. Plain radiographs demonstrated hyperostosis of the stern- oclavicular joints. The pain was relieved by non-steroidal anti-inflammatory drugs (NSAIDs). In 2001, he noticed pain in the right knee and foot, and visited another clinic. He was referred to us after plain radiographs had demonstrated bone tumors in his right femur and right 5th metatarsal bone. On examination, acne conglobata was found on his head and many acne scars, on his trunk. A bony mass was palpated on the posterior aspect of the medial condyle of the right femur. The range of motion of the right knee was slightly restricted. A mild swelling was seen on the lateral side of the right foot. No redness, tenderness or local heat was found. Laboratory examination revealed a slight elevation of ASO titer (272 Todd). White blood cell count (8,900/ml) and C-reactive protein level (0mg/dl) were normal. Fungal and microbacterial cultures of throat swabs were negative. Plain radiographs showed a mixture of sclerotic and erosive lesions in the sternum including the sternoclav- icular and 1st sternocostal joints. The distal metaphysis of the right 5th metatarsal bone was slightly enlarged with dens sclerosis. A tumor-like bony lesion was seen on the medial condyle of the right knee (Fig 1). All lesions were clearly visualized by computed tomography. The lesion of the right femur was in continuity with the underlying cortex. It had irregular surface and hypertrophied lamellar structures inside (Fig 2). Magnetic res- onance imaging demonstrated low signal intensity on T1 weighted image, heterogeneous intensity on T2 weighted image in the tumor-like lesion. This lesion and the surrounding soft tissues were enhanced after administration of paramagnetic contrast medium (Fig 3). Bone scintigram showed increased uptakes in the anterior chest wall, right distal femur, and right distal 5th metatarsal bone. Bone biopsies of the lesions at the right femur and 5th metatarsal bone were per- formed. All specimens were negative for neoplastic disease. Histological examination of 244 Fig 1. Plain X-ray examination revealed mixture of hyperostosis of sternocostoclavicular region (a), sclerosis (arrow) of the right distal 5th metatarsal bone (b) and tumor-like bony proliferative lesion (arrow) (c) in his right knee medial condyle. 1a 1b 1c 2a 2 b Fig 2. The lesions (arrow) (a: metatarsal lesion, b: distal femoral lesion) were clearly visualized by computed tomography. The tumor of the right femur was in continuity with the underlying cortex. It had irregular surface and hypertrophied lamellar structures inside. the specimens demonstrated thickened sclerotic trabeculae and marked bone marrow fibrosis with some chronic inflammatory cells (Fig 4). Fungal and microbacterial cultures were negative. The patient was diagnosed having SAPHO syndrome because of the presence of polyostotic osteomyelitis or bone tumor like lesions, acne, and the histolo1ogical fea- tures of the biopsy specimen. The pain in the right knee and right foot disappeared soon after biopsy. However, skin lesions repeated remission and aggravation. The pain and swelling in the right foot recurred after eight months and disappeared two months later. No progression of the bone lesions was found on plain radiograms within 4-years follow-up. 246 Fig 3. Magnetic resonance imaging demonstrated a femoral lesion (arrow) with low signal intensity on T1 weighted image (A), heterogeneous intensity on T2 weighted image (B) in the tumor. The tumor and the surrounding soft tissues were enhanced after administration of paramagnetic contrast medium (C). Fig 4. Histological examination of the biopsy specimen demonstrated chronic inflammatory changes, with sclerotic bone trabeculae, prominent bone marrow fibrosis, and scattered lymphocytes. The histological diagnosis was old osteomyelitis. (A: low power view x10, B: high power view x 40) DISCUSSION In 1961, Windom et al. were the first to describe musculoskeletal problems associated with acne conglobata [4]. In 1987, Chamot et al. first proposed an acronym SAPHO syndrome, to describe a group of bone and joint abnormalities associated with skin lesions [1]. Prior to the creation of this acronym, some 250 cases of hyperostosis of the chest wall with pustular eruption in hands or soles had been reported with over 50 des- ignations [5]. Most cases have been reported from Japan and Northern and Western Europe, with a few cases described from United States, Canada, and Great Britain[3]. In Japan, SAPHO syndrome has been paid little attention, probably due to that bone lesions are usually localized to the anterior chest wall and have diagnosed as sternocos- toclavicular hyperostosis without checking skin lesions. Mixture of bone sclerosis and atrophy suggestive of osteomyelitis is one of the bony features of SAPHO syndrome. Hypertrophic bone lesions are often seen in the anterior chest wall. When the anterior chest is involved, adjacent ligaments are also involved by the ossifying process, with production of a sclerotic enthesopathy[3]. Radiographic changes of the long bone lesions usually suggest either infectious osteomyelitis or a primary bone neoplastic lesion, mainly Ewing’s sarcoma [3]. In the present case, the location of the femoral lesion well coincided with the attachment of the medial head of the gastrocnemius muscle. The traction of this muscle is thought to be one factor, caus- ing a cauliflower-like bone protrusion. The patients with skin trouble like acne, when having tumor or osteomyelitis like bony lesions should be suspected to have this syn- drome. In 1999, Reith reported that histological findings vary depending on the stages of the disease process. Early lesions contain acute inflammation, edema, and prominent periosteal bone formation, whereas late lesions demonstrate markedly sclerotic bone trabeculae with prominent marrow fibrosis and only mild chronic inflammation [6]. In the present case, four months’ duration of symptoms and the histological findings are well consistent with late lesions. Treatment for SAPHO syndrome has not been standardized yet. NSAIDs are com- monly used. However, their efficiency is neither consistent nor complete [2]. Corticos- teroids or methotrexate have proven useful in most severe forms, but the efficacy has been variable [7]. In Japan, tonsillectomy has been performed in order to alleviate clin- ical symptoms associated with the SAPHO syndrome, as the manifestation may be regarded as diseases of focus tonsillitis. However, tonsillectomy was not found to bring any improvements to deformed joints or to reduce intractable pain of sternoclav- icular hyperostosis[8]. For the present case, NSAIDs was effective with temporally relief of pain. 247 REFERENCES 1. Chamot AM, Benhamou CL, Kahn MF, Beraneck L, Kaplan G, Prost A (1987) Acne-pustulosis- hyperostosis-osteitis syndrome. Results of a national survey. 85 cases. Rev Rhum Mal Osteoar- tic, 54: 187-196. 2. Kahn MF, Khan MA (1994) The SAPHO syndrome. Baillieres Clin Rheumatol, 8: 333-362. 3. Kahn MF, Chamot AM (1992) SAPHO syndrome. Rheum Dis Clin North Am, 18 : 225-246. 4. Windom RE, Sanford JP, Ziff M (1961) Acne conglobata and arthritis. Arthritis Rheum, 4: 632- 635. 5. Gmyrek R, Grossman ME, Rudin D, Scher R (1999) SAPHO syndrome: report of three cases and review of the literature. Cutis, 64(4): 253-258. 6. Reith JD, Bauer TW, Schils JP (1996) Osseous manifestations of SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome. Am J Surg Pathol, 20: 1368-1377. 7. Hayem G, Bouchaud-Chabot A, Benali K, Roux S, Palazzo E, Silbermann-Hoffman O, Kahn MF, Meyer O (1999) SAPHO syndrome: a long-term follow-up study of 120 cases. Semin Art- hritis Rheum, 29: 159-171. 8. Kataura A, Tsubota H (1996) Clinical analyses of focus tonsil and related diseases in Japan. Acta Otolaryngol Suppl, 523: 161-164. Corresponding author: Masahito Hatori, M.D., Assistant Professor Department of Orthopaedic Surgery, Tohoku University School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, Japan 980-8574 Tel: 81-22-717-7245, Fax: 81-22-717-7248 E-mail: mhato@mail.tains.tohoku.ac.jp 248