Lipoid Proteinosis Workup

Updated: Mar 11, 2022
  • Author: Dirk M Elston, MD; Chief Editor: William D James, MD  more...
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Workup

Laboratory Studies

No laboratory findings are consistently abnormal. The erythrocyte sedimentation rate may be elevated and is thought to be a result of increased production of alpha- and beta-globulins.

Polymerase chain amplification and direct nucleotide sequencing of the ECM1 gene can confirm the diagnosis.

Immunolabeling of affected tissue with polyclonal antibodies against the ECM1 protein may provide a faster, more efficient way of detecting mutations in the near future. [18]

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Imaging Studies

The dense calcifications distributed symmetrically throughout the bilateral medial temporal lobes that are characteristic of lipoid proteinosis appear bean-shaped or curvilinear on computed tomography. These calcifications also appear in the corpus striatum. Amygdala involvement is pathognomonic and becomes more prominent throughout the course of the disease. On magnetic resonance imaging, the lesions are hypointense on T1- and T2-weighted images. The lesions are best viewed on MRI gradient echo or susceptibility-weighted imaging. [7]

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Histologic Findings

Early lesions have eosinophilic hyaline thickening of papillary dermal capillaries. Later, hyperkeratosis is present, and the papillary dermis is widened by hyaline material arranged perpendicular to the basement membrane zone. Hyaline deposits may be arranged around the hair follicles, eccrine glands, sebaceous glands, and arrector pili muscles and nerves in an onionskin arrangement. The hyaline material stains positively with periodic acid-Schiff stain and is resistant to diastase. It also stains positively with colloidal iron and Alcian blue at a pH of 2.5 and with Sudan black and oil red O. It stains negatively with Congo red, and contains basement membrane components including type IV collagen, laminin, perlecan, and nidogen. [19]

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