At laparotomy, a tumor arising from the right diaphragm and protruding into the liver was discovered (Figure 3). It was surgically removed. Histologic examination revealed a leiomyoma. The patient was discharged on postoperative day 9 and had no further symptoms.
Operative view of the diaphragmatic tumor protruding into the liver.
Leiomyomas are benign smooth muscle neoplasms. They can occur in any organ, but the most common forms occur in the female reproductive tract and represent the most frequently diagnosed gynecological tumors, occurring in 20% to 50% of women older than 30 years.1 Estrogen and progesterone usually stimulate their growth, and hormone suppression may hence decrease their size. Some uncommon cases have been reported in the stomach, the small bowel, and the esophagus,2 but to our knowledge, ours is only the third case of diaphragmatic leiomyoma reported in the medical literature.3,4
We suspect that the diaphragmatic involvement was secondary to the seeding of tumoral cells disseminated during the laparoscopic myomectomy 7 years prior, probably owing to tumor morcelation. However, it is well known that uterine leiomyoma can also metastasize to different organs, even though it is seemingly benign. Such benign metastasizing leiomyomas were reported in 54 cases from 1973 to 1999.5,6Because these masses are mostly asymptomatic, they often grow large before they are detected and so can protrude into the liver, mimicking a hepatic tumor in the case of diaphragmatic location. They may be suspected to be tumors on chest radiography, which may reveal an elevation of the diaphragmatic shadow. A CT scan or an MRI scan is useful to localize the tumor and determine its relationship with other organs, although in some cases they can easily be misdiagnosed as hepatic masses. The presence of a diaphragmatic artery vascularizing the tumor should help the surgeon to suspect a diaphragmatic tumor.
Rarely, uterine leiomyoma may undergo malignant degeneration to leiomyosarcoma. The true incidence of malignant transformation is difficult to determine because leiomyomas are common, whereas leiomyosarcomas are rare and can arise de novo. Although the incidence of malignant degeneration has been estimated to be as low as 0.2%,7 radical surgery is the best option treatment to prevent this risk.
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Correspondence: Julien Jarry, MD, Hôpital Saint Andre, 1 rue Jean Burguet, 33075, Bordeaux, France (firstname.lastname@example.org).
Accepted for Publication: April 30, 2009.
Author Contributions:Study concept and design: Jarry and Shekher. Analysis and interpretation of data: Leblanc and Saric. Drafting of the manuscript: Jarry and Shekher. Critical revision of the manuscript for important intellectual content: Leblanc. Statistical analysis: Jarry and Saric. Study supervision: Leblanc and Saric.
Financial Disclosure: None reported.
This article was corrected online for typographical errors on 4/19/2010.
Image of the Month—Diagnosis. Arch Surg. 2010;145(4):398. doi:10.1001/archsurg.2010.28-b