Eccrine porocarcinoma shares dermoscopic characteristics with eccrine poroma: A report of three cases and review of the published work

Abstract

Eccrine porocarcinoma (EPC) is a rare malignant skin tumor presumably arising from the intraepidermal ductal portion of the sweat gland. EPC occasionally mimics eccrine poroma (EP), seborrhea keratosis (SK), basal cell carcinoma (BCC), pyogenic granuloma (PG) and amelanotic melanoma with its clinical appearance as a pink nodule. Dermoscopy is an invaluable technique in diagnosing skin tumors. However, few cases of EPC have been reported using dermoscopic images, and their details were not well examined. Here, we present three histopathologically proven cases of EPC and summarize their dermoscopic findings together with five previously reported cases. None of the eight cases showed dermoscopic evidence indicative of SK (comedo-like openings, milia-like cysts, fissures and ridges, and hairpin vessels with white halo), BCC (blue-gray ovoid nests, multiple blue-gray globules, wheel-like structures, shiny white areas, leaf-like areas and arborizing vessels) or PG (reddish homogeneous area with collarette and white rail lines). A milky red area, which was suggestive of amelanotic melanoma, was not detectable in any cases. Seven cases exhibited a polymorphous vascular pattern mainly consisting of hairpin, linear-irregular and dotted vessels. A combination of round-to-oval pink-white structureless areas and white-to-pink halo was observed in five of eight cases, with one case showing the white-to-pink halo alone. Our investigation revealed that the dermoscopic characteristic of EP was also observed in discrete areas of EPC lesions. Thus, it is possible that the histopathological architecture of EPC contains portions of benign EP-like components. Awareness of this dermoscopic aspect of EPC may be helpful when diagnosing pink nodules.

Dermoscopic findings of Kaposi sarcoma and dermatopathological correlations

“…The collarette sign has been reported in clear cell acanthoma, pyogenic granuloma, melanoma, basal cell carcinoma, angiokeratoma, Spitz naevus, eccrine poroma and rarely in Kaposi sarcoma . Zaballos and colleagues evaluated the dermoscopic findings of pyogenic granuloma, and in their study, the collarette sign was observed in three Kaposi sarcoma lesions.…”

“…2,16 The collarette sign has been reported in clear cell acanthoma, pyogenic granuloma, melanoma, basal cell carcinoma, angiokeratoma, Spitz naevus, eccrine poroma and rarely in Kaposi sarcoma. [17][18][19][20] Zaballos and colleagues 20 evaluated the dermoscopic findings of pyogenic granuloma, and in their study, the collarette sign was observed in three Kaposi sarcoma lesions. Histopathological correlation of the collarette sign in pyogenic granuloma was defined as hyperplastic adnexal epithelium that partially or completely surrounds the tumour.…”

Porocarcinoma of the nail: A dermoscopic observation

“…Previously reported cases revealed the presence of polymorphous vascular pattern (hairpin, linear-irregular, dotted vessels), round-to-oval pink-white structureless areas and white-to-pink halo. [8][9][10] In the differential diagnosis, a wide spectrum of cutaneous pink tumours revealing polymorphous vascular pattern on dermoscopy should be considered, including eccrine poroma, amelanotic melanoma, non-melanoma skin cancer and pyogenic granuloma. 8 Wide surgical resection is currently the treatment of choice and should be accompanied by assessment for metastatic disease, as the presence of metastases was found in 31% of previously reported cases.…”

“…[8][9][10] In the differential diagnosis, a wide spectrum of cutaneous pink tumours revealing polymorphous vascular pattern on dermoscopy should be considered, including eccrine poroma, amelanotic melanoma, non-melanoma skin cancer and pyogenic granuloma. 8 Wide surgical resection is currently the treatment of choice and should be accompanied by assessment for metastatic disease, as the presence of metastases was found in 31% of previously reported cases. 1 Based on this case, it seems that nail porocarcinoma shares dermoscopic features of porocarcinoma at different anatomical locations.…”

Características clínicas y dermatoscópicas del poroma ecrino

“…1,5,8,9 Además se puede observar áreas sin estructura y cordones blanquecinos interconectados, siendo esto último altamente sugerente de poroma. 1 En la variante pigmetada se ha descrito la presencia de estructuras azul blanquecinas y globulillares inespecíficas y aperturas tipo comedón.…”