Monday, September 26, 2005

What Causes Bony Masses in the Foot? Patient Presentation A 10-year-old male came to clinic because of a 'lump' on the underside of his middle right toe that he had noted 3 days previously while washing his feet. It was not painful and had no swelling or tenderness. He denies any recent or distant past trauma including a foreign body. He has had no problems walking and denies constitutional symptoms. The past medical history shows that he has been healthy. The family history includes diabetes in older family members. There are no cancer, bone or skin disorders in the family The review of systems is non-contributory. The pertinent physical exam shows a healthy male with growth parameters in the 25-50%. His skin examination is normal. He has shoddy anterior cervical and inguinal lymph nodes. On the ventral surface of his right middle toe is a 2-3 mm firm nodule that is slightly mobile and lying over the proximal phalynx. There is no discoloration, edema or tenderness. There is full range of motion in all joints of the toe and rest of the foot. The physician's differential diagnosis at this point included a gangion cyst, unrecognized foreign body, bony tumor, corn, bunion, or sesamoid bone. Because of the location, a corn, bunion and sesamoid bone were unlikely. The radiologic evaluation of the toe was negative for a radioopaque foreign object, periosteal reaction or bony tumor. The diagnosis of ganglion cyst was made based upon the physical examination and negative radiograph. The patient and his father were told the natural course of ganglion cysts which may remain stable in size for months to years. He was told that sometimes because of the location that the cysts are drained or removed. His father was also told to report any symptoms of significant disease such as fever, bleeding, pain etc. in the unlikely event that they were to occur in the future. Discussion Ganglion cysts are benign synovial cysts that occur commonly in the wrist, knees or other joints. In the knees, they are commonly called Baker cysts. In the wrist they are commonly called bible bumps because some people would take the largest book in the house, often the bible, and hit them to burst the cyst. Ganglion cysts, are soft, semi-mobile, may transilluminate, and occasionally are painful. Most cysts will spontaneously remit over 2 years. They may be drained or excised if they becomes extremely large, or become painful or cause a loss of function. Unfortunately there can be a high rate of recurrence. Learning Point A differential diagnosis of a bony mass often conjures up a malignant process. However, many bone masses are benign. The differential diagnosis includes: Non-oncologic Bunion Corn Foreign body Ganglion cyst Myositis ossificans Sesimoid bone Oncologic Benign Chondroblastoma Aneuysmal bone cyst Simple bone cyst Enchondroma Eosinophilic granuloma Exostosis Fibrous cortical defect and non-ossifying fibroma Osteoblastoma Osteochondroma Osteoid osteoma Malignant Ewing's sarcoma or primitive neuroectodermal tumor Osteosarcoma Metastatic tumor Rhabdomyosarcoma Questions for Further Discussion 1. What is the current standard initial evaluation for children with a malignant bone tumor? 2. What are indications for referral to a podiatrist? Related Cases Disease Ganglion cyst Foot Injuries and Disorders Wrist and Arm Injuries and Disorders Symptom/Presentation Mass or Swelling Specialty Oncology Orthopaedic Surgery and Sports Medicine Age School Ager To Learn More To view pediatric review articles on this topic from the past year check PubMed. To view current news articles on this topic check Google News. Rudolph CD, et.al. Rudolph's Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:2249-2250, 2453-2454. Fleisher GR, Ludwig S. Synopsis of Pediatric Emergency Medicine. Williams and Wilkins. Baltimore, MD. 1996:134. Author Donna M. D'Alessandro, MD Associate Professor of Pediatrics, Children's Hospital of Iowa Date September 26, 2005 Posted by Donna D'Alessandro, M.D. on 9/26/05; 8:06:57 AM Discuss