Case report: - A case report on adult-onset cystic hygroma and literature review.

Introduction: Cystic hygromas are benign lesions arising due to an abnormality of lymphoid development and rarely present in adults.

Case Presentation: We present a case of a 25-year-old girl who presented with a complaint of left lateral neck swelling of 06 years duration which was painless and increased in size progressively associated with this she had some difficulty turning her neck to the left side of a year duration. On physical examination, it was noticed that she had a 15 ∗ 12 cm soft, non-tender mass over the left lateral neck from the sub-mandibular area to the supraclavicular area, anterior and posterior to the sternocleidomastoid muscle. She was investigated with Complete blood count, neck ultrasound, and head and neck CT scan with contrast. With a diagnosed Cystic hygroma she was managed through elective surgical excision and the histopathology report suggestive of lymphatic malformation. The work has been reported in line with the SCARE criteria.

Clinical Discussion: Cystic hygroma is a lymphatic malformation that occurs as a result of sequestration or obstruction of developing lymph vessels. It can either be congenital or acquired which commonly occur in the head and neck region. Symptoms and presentation consist of swelling and cystic growths, impact on adjacent organs and structures, and potential pain or discomfort.

Conclusion: Cystic hygroma in adults is a rare condition with variable presentation. The management of these lesions is complex and multidisciplinary and depends on expertise and experience. The mainstay of treatment is complete excision.