Rapidly enlarging axillary cystic hygroma in a 6-year-old male patient: A case report and literature review.

Introduction: Cystic hygromas are relatively uncommon tumors of lymphatic origin, it appears most of the time, approximately 90 % before age of 2 years, and it is caused by abnormal development of lymphatic vessels.

Case Presentation: Here we report a case of axillary cystic hygroma in a 6-year-old healthy boy, which presented with the rapid development of a right axillary mass during 3 days, without any predisposing factor.

Discussion: Cystic hygromas occur due to complete or partial obstruction of lymphatic vessels, which leads to lack of communication with the venous system, this results in the accumulation of lymphatic fluid and swelling, it occurs in the cervicofacial region most of the time 75 %, but it can arise anywhere in the body, it classically presents as painless, soft mass, diagnosis can be done using ultrasound, CT, MRI, each of which has its advantages, surgical treatment is routinely favored, but other options are also available.

Conclusion: Axillary cystic hygromas are quite rare, few cases have been reported in fetuses and adults, but only one case in the pediatric age group, thus, in light of these cases, cystic hygromas should be considered in the differential diagnosis of any cystic axillary swelling.