A female infant of 15 months presented with a mass in the left axilla and neck which had been present since birth. In the week before admission the axillary lump had increased in size and become firm. On examination there was a fluctuant painless swelling in the left side of the neck and a firm, tender multilocular cyst in the axilla. The axillary mass was removed at operation but the patient died post-operatively. No definite cause of death was found at necropsy.
The specimen is a slice of tissue 13 cm in maximum diameter mounted to display the cut surface. Attached to the surface on the right is a strip of skin loosely attached by adipose tissue. The cut surface is pale brown and presents many cysts ranging from 1 mm to 5 cm in diameter. Several cysts have transluscent walls while others are thick-walled and show trabeculation. Some cysts intercommunicate, others do not. On the right side the mass is more solid and shows flecks of yellow fatty tissue. This is an example of a cystic hygroma.