A cystic hygroma (or haemangiolymphoma) is defined as a benign proliferation of lymphoid tissue, and is usually considered as a congenital lesion.1 It is well recognised in paediatric practice but seldom presents de-novo in adulthood.2

The embryological derivation of lymphoid tissue was described by Sabin in 1909 as arising from 5 primitive buds developing from the venous system. These are: paired jugular sacs; paired posterior sacs; and a single retroperitoneal sac. Hygromas are probably the result of sequestration of lymphatic tissue that has retained its potential for growth in any of these areas.3 Three types are described: (1) capillary - characterized by small, thin walled lymphatic channels; (2) cavernous - with large channels with a fibrous coat; and (3) cystic - characterised by large cystic endothelial lined spaces.

Cysts can be multiple and present in the neck or as a retroperitoneal abdominal mass.4 Diagnosis in the child is usually straightforward but can present problems in the adult due to its rarity. We present a case of 30 years old adult female who presented with cystic lymphangioma of neck.

We present a case of 30 years old female who presented to us with asymptomatic swelling on the right side of neck since one year. On clinical examination there was a discrete fluctuant, transilluminant swelling measuring 6 cms X 3 cms in the right supraclavicular fossa. It was non-pulsatile with no regional lymphadenopathy. Magnetic resonance imaging (MRI) scan showed well defined lobulated cystic lesion with no intrathoracic extension (Fig. 1). Thus a provisional diagnosis of lymphangioma was made. Patient was worked up for surgery. Excisional biopsy was done under general anaesthesia. Intra-operative findings revealed a thin walled lobulated cyst separate from the surrounding structures. Post-operative course was uneventful. Histopathology report confirmed the diagnosis of cystic lymphangioma. Follow-up of six months has shown patient to be disease free. The case is reported due to rarity of cystic lymphangioma in adults.

Fig. 1 : MRI scan showing Lymphangioma in the right supraclavicular region of the neck.

Cystic lymphangioma or hygroma (CL) is a rare benign pathology of the lymphatic system characterized by multiple cystic, often non-communicating concamerations. Such lesions are most often seen in infancy and in 80% of the cases they appear within the first two years of life. It is well recognised in paediatric practice but seldom presents de-novo in adulthood , with only 91 cases described in the literature.2

Lymphangioma has been classified into three groups: (1) lymphangioma simplex; (2) cavernous lymphangioma; and (3) cystic lymphangioma or cystic hygroma.3 The embryological derivation of lymphoid tissue was described by Sabin in 1909 as arising from 5 primitive buds developing from the venous system. These are: paired jugular sacs; paired posterior sacs; and a single retroperitoneal sac. Hygromas are probably the result of sequestration of lymphatic tissue that has retained its potential for growth in any of these areas.3

Cases presenting in adulthood often follow trauma or a preceding upper respiratory infection, whereas in a child the lesion is usually obvious from birth.5 Cervical lesions in a child can cause dysphagia and airway obstruction but this is rare in the adult.1 In adults there is usually a well-defined capsule but this is less distinct in children. In lesions diagnosed pre-natally, before 30 weeks, chromosomal abnormalities are common.1 Our patient was a 30 years old female who presented with asymptomatic swelling on the right side of neck since one year.

Many authors stress the importance of pre-operative imaging to look for intrathoracic extension, which is present in 10% of cases. Ultrasonography or magnetic resonance imaging (MRI) is recommended. Oropharyngeal endoscopy can identify oropharyngeal extension, which is present in 20% of paediatric cases.1 In our case MRI was done to rule out intrathoracic extension.

The treatment of choice is surgical excision but this can be technically demanding, especially if an intra-thoracic extension is present. There is a 15% recurrence rate if the lesion is not fully excised. Laparoscopic techniques have been used in both diagnosis and treatment of retroperitoneal cystic hygromas;6 laser therapy for oropharyngeal extension has been used to good effect.1

Intra-lesional injections used include OK-432, of which there are encouraging reports in a small number of cases;7 and intra-lesional Bleomycin and fibrin tissue sealant, both of which have been shown to be beneficial.8,9 Intravenous cyclophosphamide has also been used, with some success, in recurrent lesions following surgery.10 Injection of hydrocolloid dental impression material has been also used to remove a lymphangioma in an adult.11

This case was unusual in that a large cervical cystic hygroma presented de-novo in an adult with no history of trauma or upper respiratory infection. This presented a diagnostic challenge due to the rarity of the lesion in adults. Complete excision was successful and the prognosis is good. We would like to emphasise to keep cystic lymphangioma as a differential diagnosis for a cystic neck swelling in adults as well as the importance of pre-operative imaging especially for ruling out intra-thoracic extension in the management of these lesions.