A clinicopathological study of primary localised cutaneous amyloidosis

<p class="abstract"><strong>Background:</strong> Amyloidosis is defined as extracellular deposits of heterogenic, misfolded proteins, amyloid fibrils, in various tissues. The term primary cutaneous amyloidosis (PLCA) usually includes macular amyloidosis (MA), lichen amyloidosis (LA) and nodular amyloidosis. Primary cutaneous amyloidosis is very common in Kerala probably due to socio-cultural practices. There has been no published data on PLCA from Kerala thus we undertook this study. The objectives of the study were to correlate clinical features of primary localized cutaneous amyloidosis with histopathologic findings; to evaluate the sensitivity of Congo red staining with polarized light in histopathologically proven primary localized cutaneous amyloidosis)</p><p class="abstract"><strong>Methods:</strong> We undertook an observational analysis for a period of 2 years from May 2012 to April 2014 in the Department of Dermatology, Amrita Institute, Cochin. All cases clinically diagnosed as cutaneous amylodosis were included in the study. After informed consent, skin biopsy was taken. The histopathologic sections were stained with Congo red and seen under polarized microscopy for apple green birefrengance.<strong></strong></p><p class="abstract"><strong>Results:</strong> A total of 70 patients were included in the study. Of the 70 cases, there were 20 males and 50 females. The most common clinical type was lichen amylodosis observed in 32 patients followed by macular amylodosis (28) and biphasic amyloidosis (10) cases. Histopathological compatibility was seen in 71% of MA and 89% cases of LA. Congored positivity was seen in 53.8%. Congored stain under immunofluorescence microscopy was done for 30 patients which gave a positivity of 85% which indicates that it is more sensitive that polarizing microscopy.</p><p><strong>Conclusions:</strong> Our study showed that the most common type is lichen amylodosis. Histopathology and congo red staining with polarized light is a valuable aid in diagnosis. Congo red stain under immunofluorescence microscopy has greater sensitivity and improves the diagnostic yield. </p>