Atypical Clinical Presentation of Childhood Osteosarcoma: Case Report

Aim: Highlight childhood Osteosarcoma as uncommon in a pre-adolescent female’s scapula.

Presentation of Case: 9-year-old female with left scapular outgrowth, weight loss, paleness cachexia and axillary lymphadenopathy. Mass measured 27 by 53 cm, hard, tender with smooth, shiny unattached skin. Shoulder and Chest CT showed huge, well demarcated, heterogenous 14.6cm by 13.4cm by 14.4cm soft tissue mass with lobulated margins on the left scapular with its lytic destruction. Multiple nodules were seen on ipsi-lateral lung involving adjacent pleura. Malignant mesenchymal moderately pleomorphic cells with large pleomorphic hyperchromatic occasionally mitotic nuclei in a fibrous background with neoplastic lacy bone trabeculae, alternating hyper-cellular and hypo-cellular areas, dilated congested vessels were visualized on histology. Metastatic Osteosarcoma was diagnosed. Neo-adjuvant chemotherapy was given. Surgical tumor debulking awaited.

Discussion: The peak age for childhood Osteosarcoma is reported as 10–14years for females and 15–19 years in males which coincides with the adolescent growth spurt in both sexes (Tanner stage 3 or Sexual Maturation Rating (SMR) 3 in girls). Our pre-adolescent patient is noteworthy hence our documentation. In children Osteosarcoma occur primarily in the metaphyseal region of tubular long bones with 42% in the femur, 19% tibia and 10% humerus. Rarely in skull, pelvis or scapular (8%). The inflammatory features seen in osteosarcoma mimic osteomyelitis, cellulitis, trauma and benign bone tumors as strong differentials. Our patient’s late presentation features rather mimic our diagnosis. Our patient’s histology support Osteoblastic Osteosarcoma with high grade histology. A variant previously reported in sacrum, iliac crest and pubis. Late presentation seen has been cited as a major factor affecting surgical method as it will in this case. Otherwise limb salvage surgery with chemotherapy remains the management with best outcome.

Conclusion: Scapular Osteosarcoma in a pre-adolescent female is an uncommon presentation, hence this report.