CLINICAL HISTORY.—A native Haitian girl, approximately 10 years old, came to the Pediatric Outpatient Department of the Albert Schweitzer Hospital, Deschappelles, Haiti, complaining of inability to move her left arm. She was accompanied by friends, so no other significant history was available.
Physical Examination.—The patient was in good nutritional status, but was unable to move her left arm. The only striking physical finding was a palpable hard mass along the midportion of the left humerus, and a smaller firm mass about the left elbow. A radiograph was obtained.
This disease is one of the varieties of he terotopic ossification. It is considered rare and according to Mercer and Duthie,1 the preponderance ratio of male to female is 4:1.
It starts in infancy or early childhood and is characterized by the replacement of muscles, tendons, and aponeuroses by masses of bone. The ossification of the various structures progresses with