Cystic Lymphangioma of the Rectus Abdominis Muscle: An Extremely Rare Clinical Entity

Cystic lymphangioma is a rare malformative benign tumor of the lymphatic vessels. It occurs most commonly in the neck. Rarely they are known to involve the axilla, groin, mediastinum, retroperitoneum, pelvis, mesentery, omentum and spleen[1]. A 10 year old girl, without any particular pathological history, presented with complaints of swelling in the left side of abdomen increasing very slowly in size since the age of 3 years. Physical examination objectified left parietal bulk, compressible, by 5 cm long axis without signs of acute inflammation. Abdominal US showed a left paramedian parietal mass sub umbilical developed at the expense of the rectus abdominis muscle. This mass was well limited, measuring 57×41 mm, hypoechoic, micro cystic with many thin septa. She arrived deeply in contact with bowel loops and iliac vessels. Further exploration by MRI showed a polylobed mass, developed at the expense of the rectus abdominis muscle. It extended to the large muscles of the ipsilateral side, with a hypo-signal T1 and hyper-signal T2. This formation was responsible for ascension of small bowel and came in contact with the external iliac pedicle, the left psoas muscle and the sigmoid without invasion. The MRI appearance was compatible with a cystic lymphangioma. Per operatively, the cystic mass was attached at the rectus abdominis muscle (Fig. 1). Entire dissection and excision of the mass sacrificing a musculofacia piece and a tab of the parietal peritoneum were performed. There was no adhesion with the iliac vessels.