Other Neck Masses

Cervical teratoma:  Sagittal scan of the thorax and neck: solid-cystic mass (*) lateral to the neck (arrowhead = spine)

Fetal goiter :  Large complex mass at the anterior aspect of the neck, postnatally proven to be goiter

Cervical Teratomas

Teratomas are neoplasms derived from pleuripotent cells and are composed of a diversity of tissues foreign to the anatomic site in which they arise.

Incidence: Rare, may be 1 in 20,000 to 1 in 40,000 live births. It most commonly occurs in the sacrococcygeal area and the neck accounts for about 5% of teratomas.

Sonographic findings:

  • Typically, solid cystic, beginning with cystic masses and becoming larger and more complex with gestational age.
  • Usually unilateral with an anterolateral location.
  • Calcification seen in nearly half of the cases.
  • Sometimes hyperextension secondary to a pressure effect of the large mass.
  • Hydrops fetalis and hydramnios noted in 30% of cases.
  • Three-dimensional ultrasound and color Doppler ultrasound showing intense arterial and venous flow with low resistance indices may be helpful.
  • The main differential diagnoses include lymphangioma, hemangioma, or goiter.

Associations: Rarely related to other anomalies.

Management: Fetal resection or termination of pregnancy may be offered for a large mass with hydrops before viability. Cesarean section should be considered in the case of a large mass. The ex utero intrapartum treatment (EXIT) or operation on placenta support (OOPS) has been proposed in cases of potential airway obstruction.

Prognosis: Benign in more than 90% of cases but there is a high mortality rate mainly due to respiratory obstruction, prematurity and hydrops fetalis; definitive surgery may result in good outcome.

Recurrence risk: Rare.

Cervical meningomyelocele

(See spina bifida.)

Occipital Cephalocele

(see details in Part I)

Hemangioma/Lymphangioma

Hemangioma is a proliferation of vascular endothelium that may occur anywhere in the body including the face and neck, although this is relatively rare. Lymphangioma is a congenital malformation of lymphatic vessels. Hemangioma and lymphangioma show overlapping pathologic and sonographic features.

Incidence: Rare in fetal life, but rather common during the first year of life.

Sonographic findings :

  • Variable depending on types of hemangiomas; capillary, arteriovenous, or venous angiomas.
  • Hemangiomas: solid appearance due to numerous small vascular channels in most cases, but mixed solid and cystic masses are also seen.
  • Small internal hypoechoic spaces are occasionally seen.
  • Positive Doppler signal or demonstration of vascularization is helpful in the diagnosis of hemangioma.
  • Lymphangiomas: cystic mass with multiloculated areas in most cases.
  • High-out heart failure or hydrops fetalis may be noted in massive hemangioma.

Associations: Usually isolated abnormalities.

Management: In general, hemangioma/lymphangioma does not alter the standard obstetric management. Postnatal surgical correction is required for persistent cases.

Prognosis: Generally good, but prompt airway management is required in massive cases; postnatal spontaneous regression can be observed in 60% of hemangiomas.

Recurrence risk: Rare.

Goiter

Goiter is an enlarged thyroid gland, probably associated with maternal ingestion of iodides or antithyroid drugs or maternal Graves’ disease.

Incidence: Rare.

Sonographic findings:

  • Typically solid and homogeneous but occasionally hypoechoic mass which is considered abnormal if it is 2 SD above normal.
  • Symmetrical, bilobed, located at the anterior neck.
  • Hyperextension of the fetal head may be noted in cases of large mass.
  • Polyhydramnios presumably due to impaired swallowing may be observed.
  • High-output cardiac failure with cardiomegaly and pleural effusion or hydrops fetalis may occasionally occur.
  • MRI is helpful in identifying thyroid tissue.
  • The main differential diagnoses include cervical teratoma and hemangioma.
  •  Usually diagnosed in the third trimester or late second trimester.

Associations: Usually isolated.

Management: If sonographically diagnosed, accurate diagnosis of fetal thyroid status should be obtained by fetal blood sampling and intrauterine therapy may be initiated, either by reduction of maternal antithyroid medication, or intra-amniotic injection of levothyroxin in hypothyroidism, and on administration of antithyroid drugs in hyperthyroidism.

Prognosis: Good with appropriate management, however, cretinism and mental retardation secondary to hypothyroidism can occur.

Recurrence risk: Rare.

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