Primary retroperitoneal malignant melanoma.

We report a case of an extremely rare primary malignant melanoma presenting in the retroperitomeum, indurcing a diagnostic and management problem.

Osteochondroma developing from the xyphoid appendix into an abdominal wall scar from a previous laparotomy.

We describe herein the case of a 45-year-old man who developed an osteochondroma from the xyphoid appendix into an abdominal wall scar from a laparotomy performed 4 years previously. To our knowledge, rare cases of osteochondroma of the xyphoid bone have been documented in the literature. As shown by the tumor's rapid development during a period of only 4 years, osteochondromas arise from, or grow well under, inflammatory and cicatricial conditions. Periosteal contusion causing growth-plate cartilage migration and enchondral ossification seems to be the first presentation of osteochondroma.