Chronic Recurrent Multifocal Osteomyelitis - A Rare Clinical Presentation and Review of Literature.

INTRODUCTION: Chronic recurrent multifocal osteomyelitis (CRMO) is an idiopathic inflammatory disorder of bone seen primarily in children and adolescents. It is part of the clinical picture of non-bacterial osteomyelitis and typically presents a relapsing course with both remissions and spontaneous exacerbations. CRMO is typically seen in the metaphysis of long bones. Usually, the clinical symptoms include painful swellings of the affected regions. It is being reported with increasing frequency but many cases of this disease go unreported. No infective agent has been identified and antibiotics do not affect the course of the disease.

CASE REPORT: A 12-year-old girl presented with complaints of pain and swelling over both clavicles for 6 months duration. It was of insidious onset and it started bilaterally on the same day. It was not associated with fever. There was no history of trauma or any other swellings. On clinical examination, both clavicles were enlarged on medial half, non-tender on palpation and there was no local rise of temperature. The swellings were hard in consistency with smooth surface and margins were ill-defined. On examination, both shoulders range of motion were normal. There was no distal neurovascular deficits. Systemic examination was unremarkable. Blood investigations revealed erythrocyte sedimentation rate - 90, C-reactive protein - 0.6, total count - 8000. Rheumatoid arthritis factor, anti-cyclic citrullinated peptide, and anti-streptolysin O titer were negative. Hemoglobin electrophoresis was normal. Peripheral smear was normal. Sickling test was negative. Mantoux test and sputum acid-fast bacillus were also negative. Liver function tests and renal function tests, were within normal limits. No abnormalities were noted in ultrasonography abdomen. MRI of bilateral clavicle showed expansile lesions in bilateral clavicles -(medial aspect) possibility of CRMO. Histopathological examination showed mainly ossifying bone with foci of hemorrhage. Culture from the lesion showed no growth.

CONCLUSION: CRMO is a rare benign condition. A detailed history, thorough clinical examination and rationale investigations are required. Furthermore, multidisciplinary approach including pathologist, radiologist, and pediatrician is a must. Although CRMO is rare mainly because most of the cases go undiagnosed, prognosis is good without permanent skeletal abnormalities. CRMO is essentially a diagnosis of exclusion, and hence, it is paramount importance to rule out all other fatal causes before making diagnosis of CRMO.