Osteosarcoma of the middle and distal phalanges of the little toe with a cancerous ulcer

Introduction: Osteosarcoma (OS) is the most common malignant mesenchymal tumor of the bone, and mostly affects the long bones around the knee. Osteosarcoma of short tubular bones such as those of the foot is extremely rare and accounts for less than 1% of all cases. To the best of our knowledge, this is the first reported case of OS of the middle and distal phalanges of the little toe. Case Report: A 20-year-old Japanese male presented at our hospital due to pain and swelling of his left little toe for over one year. Physical examination revealed a swollen little toe on his left foot with skin ulceration and degenerative nail. Various radiological imaging tests including X-ray, CT scan, Magnetic resonance imaging (MRI) scan, positron emission tomography (PET) scan with 18F-FDG and bone scintigraphy with 99mTc -MDP showed tumors in the distal and middle phalanges of the left little toe with extraosseous masses and without distant metastasis. Open biopsy showed pleomorphic osteogenic sarcoma. After disarticulation at the metatarsophalangeal joint of the little toe, the patient received adjuvant chemotherapy with high-dose methotrexate, doxorubicin, and cisplatin. No recurrence has been observed on 12-month follow-up. Conclusion: Pleomorphic osteogenic sarcoma is rare in the feet so the initial diagnosis is often wrong, leading to delayed appropriate treatment. This case report emphasizes the need to add osteosarcoma in the differential diagnosis of the phalangeal bone tumors. (This page in not part of the published article.) International Journal of Case Reports and Images, Vol. 7 No. 3, March 2016. ISSN – [0976-3198] Int J Case Rep Images 2016;7(3):185–189. www.ijcasereportsandimages.com Matsunobu et al. 185 CASE REPORT OPEN ACCESS Osteosarcoma of the middle and distal phalanges of the little toe with a cancerous ulcer Tomoya Matsunobu, Hirofumi Bekki, Katsumi Harimaya, Yoshihiro Matsumoto, Makoto Endo, Kojiro Yoshitake, Yoshinao Oda, Yukihide Iwamoto