New dermoscopic vascular patterns in a case of eccrine poroma

Dermal Duct Tumor: A Diagnostic Dilemma

Poromas or poroid tumors are a group of rare, benign cutaneous neoplasms derived from the terminal eccrine or apocrine sweat gland duct. There are four poroma variants with overlapping features: dermal duct tumor (DDT), eccrine poroma, hidroacanthoma simplex, and poroid hidradenoma, of which DDT is the least common. Clinically, the variants have a nonspecific appearance and present as solitary dome-shaped papules, plaques, or nodules. They can be indistinguishable from each other and a multitude of differential diagnoses, necessitating a better understanding of the characteristics that make the diagnosis of poroid neoplasms. However, there remains a paucity of information on these lesions, especially DDTs, given their infrequent occurrence. Herein, we review the literature on DDTs with an emphasis on epidemiology, pathogenesis, clinical features, diagnosis, and management.

Dermoscopic-Histopathological Correlation of Eccrine Poroma: An Observational Study

Background

Eccrine poroma (EP) is a benign adnexal neoplasm that can be pigmented in 17% of cases. Four histopathological variants of EP exist. Dermoscopically, EP can mimic many other skin neoplasms.

Objectives

To provide a dermoscopic-histopathological correlation of EP, classifying the clinical and dermoscopic features of EPs on the basis of their histopathological subtype, in an attempt to better characterize these entities.

Patients and Methods

A single-center retrospective study was conducted. Clinical data were collected; patients were classified on the basis of the 4 histopathological variants of EPs. Dermoscopic images were reviewed. A dermoscopic-histopathological correlation was performed, and the results were compared with literature data.

Results

Twenty-six lesions were included, both pigmented and nonpigmented. Three of the 4 histopathological variants were identified. Different dermoscopic features were observed for each distinct histopathological subtype of EP. The lesions mimicked different types of other skin neoplasms, in particular: nonpigmented hidroacanthoma simplex resembled nonmelanoma skin cancer; pigmented hidroacanthoma simplex appeared like a seborrheic keratosis or a solar lentigo; EPs sensu stricto presented as pink nodules if nonpigmented and were similar to seborrheic keratosis if pigmented; dermal duct tumors appeared as pigmented nodular lesions.

Conclusions

Distinct dermoscopic features appeared to be recurrent in each histopathological variant. Dermoscopy can provide important clues for the diagnosis of EP; the final diagnosis is allowed by histopathology. To achieve a correct diagnosis of EP, because of its clinical and dermoscopic variability, surgical excision is recommended.

Dermoscopy of Adnexal Tumors

Cutaneous adnexal tumors include lesions with apocrine, eccrine, follicular, sebaceous, and mixed differentiation. Most are benign and sporadic, although malignant forms are occasionally observed and some cases develop in the setting of inherited syndromes. These tumors often cause immense diagnostic difficulty. Dermoscopy is a noninvasive technique that has greatly improved the diagnostic accuracy of different skin lesions, including these tumors. We provide a review of the literature on the dermoscopic structures and patterns associated with adnexal tumors. Most patterns associated with this kind of tumor are nonspecific and are observed in other nonadnexal tumors, especially in basal cell carcinomas.

Dermoscopic features and patterns of poromas: a multicentre observational case-control study conducted by the International Dermoscopy Society

BACKGROUND

Poromas are benign cutaneous sweat gland tumours that are challenging to identify. The dermoscopic features of poromas are not well characterized.

OBJECTIVE

To determine the clinical-dermoscopic features of poromas.

METHODS

Cross-sectional, observational study of 113 poromas and 106 matched control lesions from 16 contributors and eight countries. Blinded reviewers evaluated the clinical and dermoscopic features present in each clinical and dermoscopic image.

RESULTS

Poromas were most commonly non-pigmented (85.8%), papules (35.4%) and located on non-acral sites (65.5%). In multivariate analysis, dermoscopic features associated with poroma included white interlacing areas around vessels (OR: 7.9, 95% CI: 1.9-32.5, P = 0.004), yellow structureless areas (OR: 2.5, 95% CI: 1.1-6.0, P = 0.04), milky-red globules (OR: 3.9, 95% CI: 1.4-11.1, P = 0.01) and poorly visualized vessels (OR: 33.3, 95% CI: 1.9-586.5, P = 0.02). The presence of branched vessels with rounded endings was positively associated with poromas but did not reach statistical significance (OR: 2.4, 95% CI: 0.8-6.5, P = 0.10). The presence of any of these five features was associated with a sensitivity and specificity of 62.8% and 82.0%, respectively.

CONCLUSION

We identified dermoscopic features that are specific to the diagnosis of poroma. Overall, however, the prevalence of these features was low. Significant clinical and dermoscopic variability is a hallmark of these uncommon tumours, which are most prevalent on non-acral sites.

Poroma with sebaceous differentiation: dermoscopy for the diagnosis of skin tumor with sebaceous differentiation

Although divergent adnexal differentiations are occasionally seen in poroma, poroma with sebaceous differentiation is extremely rare. We present here the second case of dermoscopy on poroma with sebaceous differentiation. A 38-year-old Japanese female presented with a 2-year history of a slow-growing nodule on her left forearm. Dermoscopically, fine hairpin-like vessels, beige lobular structures were seen in the nodule. Many small yellow dots were scattered between beige lobular structures, giving orange-beige in color as a whole. On the basis of histopathologic findings, a diagnosis of poroma with sebaceous differentiation was made. Some sebaceous tumors are known to exhibit yellowish structures on dermoscopy. Tumors with sebaceous differentiation, as well as conventional sebaceous tumors, can show yellow structures on dermoscopy.

Poroma: a review of eccrine, apocrine, and malignant forms

Poroma is a benign adnexal neoplasm of the terminal sweat gland duct. Although poromas have traditionally been thought to originate from the eccrine sweat gland, there have been cases of apocrine etiology as well. Eccrine and apocrine poromas typically present as erythematous or flesh-colored nodules on the palms and soles. As these features overlap with a multitude of differential diagnoses, it is imperative to have a firm understanding of the characteristics that make the diagnosis of poroma. In addition, the malignant counterpart to the poroma, the eccrine porocarcinoma, manifests in a similar nonspecific fashion. Case studies and literature reviews have contributed immensely to our present knowledge of poroma and porocarcinoma. Given the rarity of these neoplasms, however, there remains a relative paucity of information on atypical presentations and rates of malignant transformation. In this article, the epidemiology, clinical presentation, diagnosis, and management of poroma and porocarcinoma will be reviewed. This systematic approach may serve as a guide in navigating the diagnostic dilemma of these rare cutaneous lesions.

Pigmented poroma with unusual location and dermatoscopic features

Poroma is a benign adnexal neoplasm with atn “poroid”/ductal differentiation that mimics benign and malignant skin tumors. Histopathology shows circumscribed proliferation of poroid cells intermingled with a variable number of cuticular cells. We report a case of pigmented poroma located on the face that simulated clinically and dermatoscopically a pigmented basal cell carcinoma. The features of pigmented and non-pigmented poromas were revisited in order to assist in the diagnosis.

Dermoscopy of non-pigmented eccrine poromas: study of Mexican cases

Background:

Eccrine poroma is a benign neoplasm that can mimick a malignant neoplasm dermoscopically. The characteristic vascular pattern of this tumor has not been established.

Objective:

To evaluate dermoscopic features of non-pigmented eccrine poroma in Mexican patients.

Method:

We retrospectively studied histologically proven cases of eccrine poroma from three Mexican hospitals analyzed by four dermoscopists.

Results:

Thirteen cases were studied. A polymorphous vascular pattern was found in most cases. Four presented with irregular linear and branched vessels with semi-elliptical, or semicircular endings (“chalice-form” and “cherry-blossoms” vessels). Structureless pink-white areas were the most common other dermoscopic finding.

Conclusions:

“Chalice-form” and “cherry-blossom” vessels have not been reported in other benign or malignant neoplasms and can be a useful clue to the diagnosis of non-pigmented eccrine poroma. Due to the variability of dermoscopic patterns of eccrine poroma further studies are required to establish the specificity of our findings.