Adam O’Brien, MD R1 Rib lesions in children

MB CC: 12 month old girl with 2-3 month history of left-sided “bump” on rib. Scheduled c-section at 39 weeks Uneventful infancy, meeting all milestones Mother noticed bump on chest, denies complaints from child. Was seen by her pediatrician 6 weeks previously, and instructed to watch mass for any changes until appointment with Dr. Waldhausen.

Clinic Visit MB’s mother claims that the mass has not changed in size, consistency and color No drainage, erythema or pain No history of trauma MB has been growing appropriately, can keep up with other children her age without trouble No other masses noted by mother No family history of cancer

Clinic visit continued… PE: Afebrile, vital signs normal GEN: well-appearing child, in no apparent distress CV: regular rate and rhythm, no murmurs, rubs or gallops PULM: clear to auscultation bilaterally, no wheezing or rubs. Full symmetrical expansion of rib cage MSK: left-sided mass without overlying skin lesion, approximately 1 cm x 1cm, hard, non-mobile, non-tender to palpation, fixed to ribs during inspiration/expiration.

Differential? Initial workup?

Differential Diagnoses Neoplasms: Malignant- Ewing’s sarcoma Chondrosarcoma Osteosarcoma Neuroblastoma Leukemia Metastases Benign- Osteochondroma Fibrous dysplasia Aneurysmal bone cyst Chondroblastoma Osteoid osteoma Eosinophilic granuloma Neurofibroma Trauma-fracture callous Osteomyelitis Spondylothoracic dysotosis (Jarcho-Levin syndrome) Hemangioma

Diagnostic techniques Plain films (chest x-ray) CT MRI Ultrasound PET Bone scan Biopsy

Pediatric rib lesions: a 13-year experience Kim, Lee, Arsenault, et al. Journal of Pediatric Surgery Retrospective study of primary rib lesions at Children’s Hospital Boston from , ages patients meeting inclusion/exclusion criteria Presenting signs and symptoms: pain (52%), mass noted by patient/family member (24%), incidental findings (15%), cough/SOB (9%) 16 benign, 17 malignant Benign: osteochondroma (6) > ABC > fibrous dysplasia Malignant: Ewing’s (13) >> osteosarcoma > chondrosarcoma

Study continued… Of the 16 benign tumors, 14 were preliminarily diagnosed based on x-ray and/or CT All lesions were confirmed by biopsy at some point Lesions more likely benign based on radiographic evidence can proceed directly to excisional biopsy, whereas malignant lesions should receive needle biopsy and further staging work up

MB’s chest x-ray Chest two views Findings: There is a small additional osseous structure along the left lateral rib margin, associated with either the left seventh or eighth lateral rib margin, with a likely correlate on the lateral view anteriorly. This finding corresponds to clinical exam, and may represent a benign osseous excrescence. There is mild overlying soft tissue swelling. The underlying bone appears intact. The remaining bones appear normal. Mild bilateral central perirectal thickening may represent hypoventilation or mild atelectasis. No focal peripheral consolidation worrisome for pneumonia. No pneumothorax or pleural effusion. Impression: Likely osseous excrescence arising from the left seventh or eighth lateral rib, with a normal underlying bone. This finding may be interrogated sonographically, however this osseous structure may be more definitively characterized using limited/targeted CT.

Plan: Limited CT of chest for further work-up, follow up after study

Questions?

Bibliography: Davie, A. Mark. "Imaging in Pediatric Skeletal Trauma." Springer.com. European Journal of Radiology, 6 Nov Web. 27 Sept Faro, Mahboubi, and Ortega. "CT Diagnosis of Rib Anomalies." Clinical Imaging 17.1 (1993): 1-7. Print. Kim, S., S. Lee, D. Arsenault, R. Strijbosch, R. Shamberger, and M. Puder. "Pediatric Rib Lesions: A 13-year Experience." Journal of Pediatric Surgery (2008): Print. Milbrant, Todd, Henry Iwinski, and Vishwas Talwalkar. Orthopedic Knowledge Update. 10th ed. N.p.: n.p., Print.