amyloidoses can be classified into three categories : primary localized cutaneous amyloidosis ( plca ) , secondary localized cutaneous amyloidosis , and systemic amyloidosis with cutaneous involvement . in the plca group ,
three types can be distinguished : macular , papular ( lichenoid ) and nodular forms .
the first two are mainly located on the trunk , and cytokeratins serve as the amyloid precursors . here , amyloid deposition is limited to the papillary dermis [ 1 , 2 , 3 , 4 , 5 ] . however , in the rare cases of nodular plca , amyloid consists of aggregated kappa and lambda light chains , which can be found both in the dermis and the subcutaneous tissue [ 1 , 2 , 3 , 4 , 6 ] .
furthermore , nodular plca can originate from systemic amyloidosis or progress to systemic disease [ 3 , 4 ] . here , we present a case of nodular plca on the temple of a 52-year - old woman .
a 52-year - old lady presented with a soft , shiny , partially yellow , erythematous tumor ( 3.5  4.5 cm ) with telangiectasia on her right temple ( fig .
she recalled having had this tumor for about 4 years and that it had significantly grown lately .
the diagnosis was confirmed by electron microscopy , and the typical amyloid fibrils ( 710 nm in diameter ) were found ( fig .
a punch biopsy taken during follow - up showed some remaining amyloid so that the patient is now scheduled to undergo a second surgery via curettage .
the diagnosis of plca requires histological analysis of a skin specimen , complemented by immunohistochemistry and electron microscopy .
histologically , eosinophilia as well as positivity in periodic acid - schiff , congo red , and thioflavin t stainings are characteristics of amyloid deposits [ 1 , 8 ] .
immunohistochemistry with antibodies directed against cytokeratin and immunoglobulin light chains ( lambda and kappa ) allows to further distinguish between the different forms of plca .
electron microscopy confirms the diagnosis of amyloidosis when the typical amyloid fibrils ( 710 nm in diameter ) are found .
image quality improves significantly when the skin sample is fixed in karnofsky 's fixative ( glutaraldehyde ) instead of paraformaldehyde . for patients with nodular plca
, it is recommended to asses for progression to systemic amyloidosis on a regular basis .
this should include a full history and physical examination along with electrocardiogram , complete blood count , serum creatinine levels , serum liver - associated enzyme levels , serum electrophoresis , and urine examination .
furthermore , an abdominal fat biopsy has been suggested as an easy method to detect a potential progression to systemic disease [ 3 , 7 ] .
it has to be mentioned though that nodular plca is more frequent in asia and south america when compared to europe or north america .
 a 52-year - old woman presented with a large partially yellow and erythematous tumor on her right temple . 
 she reported that it had grown over the last 4 years . 
 regional lymph nodes were impalpable . 
 a punch biopsy showed eosinophilic material in the dermis and subcutis . 
 immunohistochemistry showed positive staining for kappa and lambda light chains . 
 electron microscopy showed the typical amyloid fibrils ( 710 nm in diameter ) . 
 there was no evidence of systemic amyloidosis , paraproteinemia or underlying plasmacytoma . 
 the tumor was completely removed via curettage . at follow - up , the patient presented in good health with no signs of relapse . 