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

Navigating Head and Neck Porocarcinoma: Systematic Review with Special Emphasis on Surgical Safety Margins

Eccrine porocarcinoma, sharing many features with other skin tumours, is diagnostically challenging. A conventional biopsy might be misleading and surgical excision becomes a primary diagnostic tool and a treatment method. However, the data on surgical safety margins are not consistent. We present a systematic review analysing the surgical margins of porocarcinoma in the head and neck area, which was conducted across the PubMed, Cochrane, and Web of Science databases including studies published from inception to November of 2023. In this systematic review, the PRISMA-ScR checklist was used, and a Cohen's Kappa coefficient of 0.92 was applied, indicating very good agreement between reviewers. Out of 529 identified articles, 18 studies yielding 20 cases in total were selected for a thorough analysis. Nine (45%) cases were observed in the facial regions, eight (40%) on the scalp, and three (5%) on the neck. The primary treatment of choice was wide local excision with safety margins ranging from 3 to 22 mm (mean: 10.1). It demonstrated that surgical margins do not differ by age or anatomic regions, with the main point of reference being the tumour size. As observed, the bigger the tumour, the wider the safety margins were. However, the limited disclosure of surgical safety margins in analysed case reports impeded our ability to define the minimum safety margins. Further investigation and a consensus on recommended safety margins are required.

Eccrine poroma localized in the second toe

Eccrine poroma is a rare adult benign adnexal tumor that originates in the excretory pore of the sweat gland. It is a small reddish lesion, protuberant, fleshy, and well-defined. It is located preferably in the palms of the hands and the soles of the feet [1]. Nevertheless, it may be found on any skin part of the body's surface [2]. We report a case of eccrine poroma of relatively rare localization on the second toe of the left foot. The biopsy confirmed the diagnosis by objectifying the histological lesions corresponding with the poroma. The article aims to report an eccrine poroma located in an unusual location, surgical treatment, and follow-up.

Porocarcinoma: an epidemiological, clinical, and dermoscopic 20-year study

BACKGROUND

Porocarcinoma (PC) is a rare cutaneous adnexal tumor with a variable metastatic potential. Given the paucity of data, guidelines and specific recommendations for PC are not yet well-established. In this study, we evaluate the disease-specific characteristics and outcome of this rare and often underestimated tumor.

MATERIALS AND METHOD

A retrospective study of the epidemiological, clinical, and dermoscopic characteristics among cases of histopathologically diagnosed PC, collected from the database of two skin cancer clinics in Italy (Firenze, Pistoia) from 2000 to 2020, was conducted.

RESULTS

Among the 52 patients with 53 tumors, 31 were men (59.6%) and 21 were women (40.4%) with an age range of 49-96 years (median age 82 years). The most common locations were the head/neck region in men (34% in men vs. 17% in women) and the lower limb in women (17% in women vs. 9% in men). Forty-eight cases (91%) underwent local excision. Of these patients, two (4%) experienced local recurrence, and one (2%) developed a second PC on a different anatomical site 1 month after the primary tumor's excision. Lymph node metastases were present in three cases (6%). Two of them have been treated surgically with adjuvant radiotherapy (both are disease-free after a 2-year follow-up period), whereas the third case developed visceral metastases followed by PC-related death.

CONCLUSIONS

This study, with 52 patients with 53 tumors covering a follow-up period of more than 5 years, shows a less aggressive behavior of PC with 4% local recurrence, 6% nodal metastases, and 2% mortality.

Poroid Hidradenoma: Dermoscopic and In Vivo Reflectance Confocal Microscopic Description

Poroid hidradenoma (PH) is a rare, benign adnexal neoplasm usually presenting as a solitary, well circumscribed, asymptomatic papule or nodule that appears reddish and is occasionally tender. Since 1990, only a few cases of PH have been reported. We present a case of PH on the medial surface of the thigh and describe, for the first time, the dermoscopic and reflectance confocal microscopic (RCM) features in correlation with histology. A 67-year-old woman with unremarkable family or past medical history presented with a nodular lesion on the medial surface of the right thigh. The lesion had appeared 4 months earlier and rapidly enlarged. Physical examination revealed a 7 × 5 mm, non-tender, reddish nodule with clinically distinct margins. Dermoscopy showed central blue-grey pigmented areas, a polymorphous vascular pattern with arborizing, glomerular and hairpin vessels surrounded by white halos. RCM revealed an ovoid, well-outlined tumor, with a central area containing cells with distinctive morphologies, two types of tumor cells, tubular hypo-reflective structures, and rectilinear vessels in the stroma. These findings correlated with histological features, which established the diagnosis of PH. Even though the diagnosis of PH remains histopathological, non-invasive tools, such as RCM, can help rule out several malignancies, therefore reducing surgical-associated comorbidity.

A systematic review of periungual eccrine neoplasms

Eccrine tumors are a rare cutaneous adnexal neoplasm originating from the sweat glands. The periungual region represents an uncommon localization for these neoplasms. We analyzed all published demographic, clinical, and treatment data on periungual eccrine tumors. A systematic review following PRISMA guidelines was performed of articles published prior to March 2021. Articles were included in the review if a full-text English version was available. Of the surveyed literature, 27 full-text case reports were included in the final analysis. Benign eccrine poroma and porocarcinoma were the most common tumor subtypes (nine and eight cases, respectively). Males were only affected by poroma and porocarcinoma, while females were affected by all tumor subtypes. The first toe was the most common lower extremity affected. Misdiagnosis led to delayed treatment in 25% of cases. As such, while periungual eccrine neoplasms are rare diagnoses, the nonspecific presentations of these growths raise concerns about misdiagnosis and delayed treatment. Further research is needed related to sex-differences in the epidemiology of these growths and into the prevalence of the first toe as a location. These tumors should be considered in the differential diagnosis for nail unit afflictions.

Rare case of large eccrine poroma of the eyelid

Eccrine poroma is a rare tumor arising from sweat glands with common location being soles and palms. We are reporting a case of 70-year male patient with large lower lid mass lesion. Owing to its location and history of growth, malignancy was suspected. Biopsy proved it to be eccrine poroma which is a benign lesion. Complete excision with lid reconstruction was done. Eccrine poroma, though rare, should be kept in the differential diagnosis of eyelid tumors. Owing to the risk of malignant transformation and difficulty in clinical differentiation between poroma and porocarcinoma, wide excision should be done.

Dermoscopic features and differential diagnosis of sebaceous carcinoma

Sebaceous carcinoma is a rare malignant skin neoplasm arising from sebaceous glands. Its clinical diagnosis is difficult and reports of dermoscopic findings have been limited. This study aims to analyze its dermoscopic features and differential diagnosis in dermoscopic examination. The study included patients diagnosed with histologically proven sebaceous carcinomas as well as diagnosed cases of sebaceous hyperplasia, sebaceoma, squamous cell carcinoma and basal cell carcinoma for comparison of dermoscopic findings. The dermoscopic criterion of presence of sebaceous carcinoma was scored only if the two evaluators reached a consensus. Fifteen cases of histologically diagnosed sebaceous carcinoma were included in our study. All cases were extraocular sebaceous carcinoma. A total of 60 (15 basal cell carcinomas, 15 squamous cell carcinomas, 15 sebaceous hyperplasias and 15 sebaceomas) cases were collected for comparing dermoscopic features with sebaceous carcinoma. In dermoscopic analysis of sebaceous carcinoma, the majority of tumors (66.67%) presented polymorphic vessel pattern. Other features included whitish-pink areas (80%), yellowish structures (73.33%) and yellowish structureless areas (60%). Yellowish structures in sebaceous carcinomas are the main dermoscopic findings to differentiate squamous cell and basal cell carcinomas (P < 0.001), whereas purplish globules, shiny white blotches and strands and whitish-pink area distinguish sebaceous carcinomas from other sebaceous tumors (P < 0.05).

The transition between a poroma and a porocarcinoma evidenced by the dermoscopy

Eccrine porocarcinoma (EPC) is a rare malignant skin tumor. The dermoscopy of invasive EPC reveals focal presence of whitish-pink, structureless areas surrounded by pinkish-white halos. In an eccrine poroma (EP), such areas present diffuse distribution in the "frog- eggs" pattern. We reported an EPC in situ that presents a transitional dermoscopy pattern between EP and invasive EPC. We found a diffuse distribution; whitish-pink, structureless areas surrounded by pinkish-white halos; a central exulceration and a polymorphic vascular pattern.

Dermoscopy of squamoid eccrine ductal carcinoma: an aid for early diagnosis

Squamoid eccrine ductal carcinoma is a cutaneous malignancy that originates from the eccrine sweat gland. A 76-year-old woman presented with an asymptomatic papule on her nose that had been present for one year. Dermoscopy showed pseudocysts, irregular linear crown vessels, and yellowish-brown globules surrounded by white halos. This is the first dermoscopic description of squamoid eccrine ductal carcinoma. Studies with more cases are needed to confirm the dermoscopic characterization of this tumor.

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.