Younger Male with Abnormal Skin on Neck

Evan Farmer, M.D.

Specimen Type:

Skin

History:

10-year-old male with 2-3 year history of the neck skin appearing like a "chicken skin."

Pathologic Features:

Histologic sections show degenerative changes that affect the elastic fibers in the mid-dermis with sparing of the papillary and deep reticular dermis. The elastic fibers are readily identifiable in the H&E stained and appear irregular in contour, thickened and fragmented. The abnormal elastic fibers are arranged in a haphazard fashion and are highlighted in an elastic stain.

Differential Diagnosis:

  • Solar elastosis
  • Pseudoxanthoma elasticum
  • Drug-related pseudoxanthoma elasticum
  • Perforating pseudoxanthoma elasticum (perforating calcific elastosis)

Diagnosis:

The diagnosis is pseudoxanthoma elasticum

Pseudoxanthoma elasticum is a genetic disorder in which the elastic fibers are abnormal and have a tendency toward calcification. Pathologic mineralization of the connective tissue and other organ systems, namely, cardiovascular and eyes also occurs. The majority of the cases are autosomal recessive although few autosomal dominant familial variants have been reported. It must be noted, however that a high proportion of the clear cysts are actually due to sporadic location. The causative gene has been identified as ABCC6.

Clinically, the skin lesions consist of yellow papules particularly in the follicular regions, namely the neck, axilla, umbilicus, groin, wrist and antecubital and popliteal fossae. These lesions may be accompanied by skin laxity been described as "chicken skin" appearance.

Histologic differential diagnosis includes solar elastosis because solar elastosis, as in pseudoxanthoma elasticum, shows a normal elastic tissue. However, and solar elastosis the material is present as dense masses rather than individually altered fibers. Currently it pseudoxanthoma elasticum has been reported in patients using penicillamine or saltpeter. Periumbilical pseudoxanthoma elasticum is considered a perforating variant of pseudoxanthoma elasticum. In this area, however, the disease is localized to the umbilicus and does not have systemic involvement.

References:

  1. Coatesworth AP, Darnton SJ, Green RM, Cayton RM, Antonakopoulos GN. A case of systemic pseudo-pseudoxanthoma elasticum with diverse symptomatology caused by long-term penicillamine use. J Clin Pathol. 1998 Feb;51(2):169-71.
  2. McKee P, Calonje E, Granter S. Pathology of the Skin, With Clinical Correlations. 3rd ed. Philadelphia, PA: Mosby, 2005.
  3. Kocatürk E, Kavala M, Zindanci I, Koç M. Periumbilical perforating pseudoxanthoma elasticum, Indian J Dermatol Venereol Leprol. 2009 May-Jun;75(3):329.
  4. Laube S, Moss C. Pseudoxanthoma elasticum. Arch Dis Child. 2005 Jul;90(7):754-6.
  5. Li Q, Jiang Q, Pfendner E, Váradi A, Uitto J., Pseudoxanthoma elasticum: clinical phenotypes, molecular genetics and putative pathomechanisms. Exp Dermatol. 2009 Jan;18(1):1-11.