Primary localized cutaneous amyloidosis: a clinicopathologic study from Saudi Arabia

Primary localized cutaneous amyloidosis (PLCA) refers to deposition of amyloid in apparently previously normal skin with no evidence of deposits in internal organs. Certain ethnic groups are particularly predisposed. The objective of this study was to investigate the occurrence of PLCA in a hospital-based set-up and to review the clinico-pathologic findings of histologically confirmed cases.

Methods included a retrospective evaluation of the records and paraffin sections of skin biopsies of all patients, diagnosed clinically as cutaneous amyloidosis in a tertiary care teaching hospital during the period 1987-95.

Twenty-one out of 42 suspected cases were histologically confirmed as PLCA; the total number of biopsied patients during the whole period was 920. Eleven were cases of lichen amyloidosis (LA) and 10 were of macular amyloidosis (MA). All were adults, and women dominated in MA. The mean duration of symptoms was shorter for the latter subtype. Histologically epidermal changes were the main differentiating feature between LA and MA.

PLCA is a rare chronic progressive skin disorder affecting adults, with a prevalence of 0.15 among patients attending the dermatology clinic in a tertiary care teaching hospital in Saudi Arabia. There were few differences in demographic profile or histochemical characteristics between LA and MA. Meticulous histologic examination of sections and even sequential biopsies may be needed to confirm the diagnosis in clinically suspected cases.