|IMAGES IN RHEUMATOLOGY
|Ahead of print publication
Coexistence of fibrous dysplasia with reactive arthritis
Anupam Wakhlu1, Akhil Pawan Goel2, Rasmi Ranjan Sahoo1, Pradyumn Singh3
1 Department of Rheumatology, King George's Medical University, Lucknow, Uttar Pradesh, India
2 Department of Rheumatology, King George's Medical University, Lucknow, Uttar Pradesh; Department of Rheumatology, Manipal Hospitals, Jaipur, Rajasthan, India
3 Department of Pathology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
Akhil Pawan Goel,
Manipal Hospital, Sector 5, Main Sikar Road, Vidhyadhar Nagar, Jaipur - 302 013, Rajasthan
Source of Support: None, Conflict of Interest: None
Keywords: Arthritis, dysplasia, fibrous, reactive
A 14-year-old male presented with acute onset, asymmetrical, additive oligoarthritis involving both knees and right ankle for 1 month. His symptoms preceded with diarrhea lasting for 7 days around 1½ month back. It was not associated with oral and genital ulcers/inflammatory back pain/red eye/blood in stool/skin rash. There was no family history of arthritis or psoriasis. On examination, his BP was 100/70 mmHg, and his pulse rate was 90/min. Right ankle and both the knees were tender and swollen. Sacroiliac and hip joints were normal. The rest of the joints were normal, and there was no enthesitis. Investigations revealed hemoglobin: 10.4 g/dl, total leukocyte count: 10000/mm 3, platelet count: 3 lac/mm 3, mean corpuscular volume: 84/fl, and retic count: 1%; peripheral smear revealed normocytic normochromic anemia, erythrocyte sedimentation rate Westergen method (WG): 40 mm/1st h (10-20), C-reactive protein: 20 mg/l (0-5), serum calcium: 7.6 (8–10.5 mg/dl), ALP: 300 (65–270 IU), and Vitamin D: 15.3 IU. Liver and kidney function tests were normal. HLA-B27 (flow cytometry) was negative. Urine routine examination was normal. X-ray pelvis revealed bilateral normal sacroiliac and hip joints. However, there was a well-circumscribed cystic lesion with septations, measuring approximately 7 cm × 4 cm in the proximal shaft of femur extending into the femoral neck [Figure 1]a. It was not associated with the periosteal reaction, and the overlying cortex was preserved. Magnetic resonance imaging (MRI) of the right hip revealed a hypointense lesion on T1 and hyperintense lesion on T2 and T2 fat-suppressed images suggestive of fibrous dysplasia [Figure 1]c and [Figure 1]d. There was no evidence of sacroiliitis.
|Figure 1: (a) X-ray pelvis with both hip joints (anteroposterior view) showing well-circumscribed cystic lesion with septations in the proximal shaft of the right femur with the preserved bony cortex. (b) X-ray pelvis with both hip joints (anteroposterior view) showing stabilization with open reduction and internal fixation using dynamic hip screw. (c) Magnetic resonance imaging of the right hip and proximal femur showing low-to-intermediate signal intensity on T1-weighted images. (d) Magnetic resonance imaging of the right hip and proximal femur showing hyperintense lesion on T2 fat-suppressed sequences|
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A diagnosis of fibrous dysplasia (monostotic) coexisting with reactive arthritis was considered. The patient was given NSAIDS, calcium, and Vitamin D supplements, and the right ankle was injected with a single dose of 40 mg of injection methylprednisolone acetate, which led to significant improvement in arthritis. He underwent open bone biopsy and curettage of the lesion, followed by G-Bone application and internal fixation by dynamic hip screw [Figure 1]b. The histopathological examination of bone biopsy revealed misshapen and curvilinear bone trabeculae without osteoblastic rimming and surrounding fibroblastic proliferation in a collagenous stroma, which was consistent with fibrous dysplasia [Figure 2]a and [Figure 2]b. On the follow-up visit after 1 month, he had no arthritis.
|Figure 2: (a and b) Microphotographs showing misshapen and curvilinear bone trabeculae (indicated with an arrow) without osteoblastic rimming and surrounding fibroblastic proliferation in a collagenous stroma (indicated with arrowhead). The fibroblasts have bland ovoid nuclei without atypia. Mitosis or necrosis is not evident|
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| Discussion|| |
Fibrous dysplasia is a common benign skeletal disorder typically seen in adolescents and young adults. It is a developmental anomaly, in which the normal medullary space of the affected bone is replaced by fibro-osseous tissue. It may be monostotic or polyostotic. Males and females are almost equally affected. The monostotic form is approximately six times more common than the polyostotic form. The most common sites of skeletal involvement in the monostotic form are the ribs (28%), proximal femurs (23%), and the craniofacial bones (20%). Patients with small, monostotic lesions might be asymptomatic, with the abnormality identified incidentally on radiologic studies obtained for unrelated reasons. When present, symptoms are nonspecific and include pain, swelling, tenderness, and stress or overt pathologic fracture. The usual appearance of fibrous dysplasia on X-rays includes a lucent lesion in the diaphysis or metaphysis, with endosteal scalloping and with or without bone expansion and the absence of periosteal reaction. The matrix of the lucency is smooth and homogenous; classically, this is ground glass appearance. Irregular areas of sclerosis may be present with or without calcification. On T1-weighted MRIs, the lesion has low-to-intermediate signal intensity equal to that of muscle. T2-weighted images also show low signal intensity owing to the high content of collagen and bone. Our patient had low signal intensity of lesion on T1-weighted images, whereas T2 fat-suppressed images showed hyperintense signal, which is characteristic of fibrous dysplasia seen in children.
Incidentally found, asymptomatic, radiographically characteristic fibrous dysplasia lesions do not require further assessment and require only clinical observation. Follow-up X-rays every 6 months to look for progression has been recommended. Surgical procedures are required for the correction of deformities, prevention of pathologic fractures, or eradication of symptomatic lesions.
This case shows the rare coexistence of fibrous dysplasia with reactive arthritis. Such case has not been previously reported. No association has been found between fibrous dysplasia and reactive arthritis.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Mirra JM, Gold RH. Fibrous dysplasia. In: Mirra JM, Piero P, Gold RH, editors. Bone Tumors. Philadelphia: Lea & Febiger; 1989. p. 191-226.
Rahman AM, Madge SN, Billing K, Anderson PJ, Leibovitch I, Selva D, et al
. Craniofacial fibrous dysplasia: Clinical characteristics and long-term outcomes. Eye (Lond) 2009;23:2175-81.
Shah ZK, Peh WC, Koh WL, Shek TW. Magnetic resonance imaging appearances of fibrous dysplasia. Br J Radiol 2005;78:1104-15.
Parekh SG, Donthineni-Rao R, Ricchetti E, Lackman RD. Fibrous dysplasia. J Am Acad Orthop Surg 2004;12:305-13.
Saglik Y, Atalar H, Yildiz Y, Basarir K, Erekul S. Management of fibrous dysplasia. A report on 36 cases. Acta Orthop Belg 2007;73:96-101.
Kusano T, Hirabayashi S, Eguchi T, Sugawara Y. Treatment strategies for fibrous dysplasia. J Craniofac Surg 2009;20:768-70.
[Figure 1], [Figure 2]