REGIONAL FRONTERA SUR, ISTMO Y PACÍFICO SUR

Lymphangioma

It is a developmental malformation (hamartoma) affecting lymphatics. Primitive lymph sacs develop during sixth week of intrauterine life. Failure of a part of lymph sac to join the main lymphatic system or sequestration of a portion of jugular sac results in a lymphangioma.

The common sites for lymphangioma are: • Neck

• Axilla • Groin • Mediastinum • Retroperitoneum

In the neck, it is called as cystic hygroma (Figs 12.19A and B). Cystic hygroma is a multilocular swelling consisting of multiple cysts filled with clear lymph and lined by a single layer of endothelium. These cysts are of variable size, intercommunicating with each other and may extend between muscle planes.

Fig. 12.18A: Sternomastoid tumor left side

Fig. 12.18B: Diagrammatic representation of

sternomastoid tumor Box 12.11: Torticollis—causes • Muscular: Contracture of sternomastoid • Cervical: painful condition of cervical spine • Pharyngeal: Infections, e.g. tonsillitis • Ocular: Squint

• Intracranial: Posterior fossa tumor

• Postural _{Fig. 12.19A: Cystic hygroma neck}

Fig. 12.19B: Diagrammatic representation of

Fig. 12.20A: Branchial cyst left side

Fig.12.20B: Diagrammatic representation of branchial cyst

The cystic hygroma usually presents at time of birth or in early infancy. It may cause obstructed labor due to its large size. The location of swelling is in lower third of neck in the posterior triangle. The size of swelling may vary from small cystic mass to a huge lump occupying whole of the posterior triangle of neck extending up to cheek and ear.

On examination, the swelling is soft, cystic and partially compressible due to intercommunication of cystic spaces.

The swelling may increase in size on coughing or crying if there is intrathoracic extension. Most charac- teristic feature that distinguishes it from other similar swellings in the neck is that it is ‘brilliantly transilluminant’. Complications

a. Secondary infection leading to painful swelling and fever. It may sometimes cause spontaneous regression of the lesion.

b. Rapid enlargement of cystic hygroma may cause respiratory obstruction in infants. It may require urgent aspiration of the cyst and even tracheostomy. Treatment: Surgical excision of all the cysts and lympha- tic tissues with preservation of normal neurovascular structures.

Injection sclerotherapy was earlier used for reducing the cyst size. However, it is not as effective since the lesion is multilocular. Moreover, it destroys the adjoining normal tissues and makes dissection more difficult. Differential diagnosis: Box 12.12.

Box 12.12: Differential diagnosis of cystic swellings in posterior triangle of neck

Cystic hygroma Lipoma Hemangioma Brilliantly Transillumination Transillumination

transilluminant –ve -ve

Partly compressible Non-compressible Compressible

No skin No skin Skin

discoloration discoloration discoloration +ve Slip sign –ve Slip sign +ve Slip sign -ve Non-pulsatile Non-pulsatile Can be pulsatile

(AV fistula) BRANCHIAL CYST

Embryology

During intrauterine life in the fifth week, four branchial arches are seen on the side of neck and grooves in

between are called as branchial clefts. The first cleft persists as external auditory canal. The second branchial arch overgrows and fuses with forth arch thus obliterating the remaining three clefts. This potential space is known as “sinus of His” and persistence of this space results in development of branchial cyst.

Pathology

The cyst is lined by squamous epithelium. It contains thick turbid ‘cheesy material’ full of cholesterol crystals that is secreted by sebaceous glands in lining epithelium. Clinical Features

• Although congenital, the cyst appears at 20-25 years of age because the fluid accumulates very slowly. • There is painless swelling in anterior triangle of neck

deep to sternomastoid muscle. The swelling is located at junction of upper and middle third of sternomastoid muscle bulging through its anterior border (Figs 12.20A and B).

• The swelling is smooth surfaced, soft, cystic and fluctuant.

• On contraction of sternomastoid muscle, the swelling becomes less prominent.

• The swelling is non-transilluminant. Diagnosis

• It is essentially clinical.

• Ultrasound shows a cystic mass.

• Needle aspiration shows turbid fluid rich in cholesterol crystals.

Differential Diagnosis

• Cold abscess in the neck—secondary to tuberculous lymphadenitis. It has ill-defined margins. Multiple enlarged matted lymph nodes are palpable in the neck. Constitutional symptoms of tuberculosis like loss of weight, anorexia and evening rise of temperature may be present.

• Lymphangioma in the neck is usually seen in infants in posterior triangle and produces brilliantly transilluminant swelling.

• Carotid body tumor: It is seen in elderly patients deep to sternomastoid muscle as a solid and pulsatile swelling.

• Plunging ranula: It produces a swelling in the submandibular region that is transilluminant and bimanually palpable through oral cavity.

Complications

• Due to presence of lymphatic tissue in the wall, there can be recurrent infection in the cyst. The cyst becomes painful and exhibits signs of inflammation. • Rupture of the cyst or incomplete excision may lead

to formation of branchial sinus.

• Branchiogenic carcinoma: Very rarely, primary squamous cell carcinoma in the branchial cyst is reported. However, before making a diagnosis of this rare condition, possibility of metastasis in cervical lymph nodes from occult primary in head and neck region must be ruled out.

Treatment

Excision of the cyst is carried out through transverse skin crease incision along the Langer’s lines. The posterior wall of cyst should be carefully dissected since it may

extend up to pharyngeal wall. Its incomplete excision can lead to recurrence. One should avoid injury to spinal accessory nerve and hypoglossal nerve during dissection.