Aplasia Cutis Congenita Workup

Updated: Jun 16, 2020
  • Author: Chris G Adigun, MD, FAAD; Chief Editor: William D James, MD  more...
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Laboratory Studies

No specific laboratory abnormalities are consistently found in aplasia cutis congenita (ACC). Abnormalities due to associated conditions may be present. Chromosome analysis or genetic testing may be indicated if a pattern of abnormalities suggests a genetic disorder.

Elevated alpha-fetoprotein levels in maternal serum and amniotic fluid, as well as elevated acetylcholinesterase in amniotic fluid, have been reported as possible early signs of aplasia cutis congenita. However, these tests are neither sensitive nor specific and are not currently used for diagnosis. [62]


Imaging Studies

Imaging studies are seldom required for small circular or oval aplasia cutis congenita (ACC) of the scalp with no apparent associated anomalies.

Atypical or very large scalp defects should be imaged for possible underlying bone, vascular, or soft tissue defects. In one neonate, a ventricular diverticulum of the posterior horn of the lateral ventricle was associated with aplasia cutis congenita of the scalp. It manifested as an expanding bulge of the subdural space.

Magnetic resonance imaging of the head is recommended for evaluation of ectopic neural tissue in midline bullous or membrane scalp aplasia cutis congenita. [63] Ultrasound imaging can be used for larger nonmembranous scalp aplasia cutis congenita to evaluate for underlying bony defects. [64]

Distal radial epiphyseal dysplasia associated with aplasia cutis congenita over the dorsum of the distal forearm has been reported. Although the aplasia cutis congenita was diagnosed at birth, the radial dysplasia was not recognized until presentation to an orthopedist at age 5-10 years. Radiographs of the involved extremity should be performed in cases of aplasia cutis congenita involving the distal forearm.


Other Tests

Other tests may be indicated for evaluation of associated conditions.


Histologic Findings

The histologic features of the skin vary according to the depth of the aplasia and its duration. At birth, ulcerated lesions may show a complete absence of skin. After healing, the epidermis may appear flattened with a proliferation of fibroblasts within the connective-tissue stroma and an absence of adnexal structures. Bullous aplasia cutis congenita (ACC) is a rare clinical subtype with a distinct pattern containing fibrovascular stroma, edematous stroma, or both. Identical histologic findings are found in encephaloceles and meningoceles. The diagnosis of aplasia cutis congenita can typically be made without histological evidence, however. A biopsy may not be obtained, owing to the patient’s age. [65]