Eccrine Porocarcinoma: A Multicenter Retrospective Study with Review of the Literatures Reported in Korea

An unusual case of eccrine porocarcinoma on the axilla with nodal involvement: A case report

Ecrrine porocarcinoma, a rare aggressive skin tumor, develops from sweat glands located in lower limbs, followed by the head and neck, trunk, and upper limbs. The incidence represents only about 0.005% of all cutaneous malignant tumors. The most common site is the lower extremities in elderly patients. As it has a high chance of metastases and recurrence after surgery, mainstay of treatment modality is wide local excision or Mohs (micrographically oriented histographic surgery) micrographic surgery. Mohs micrographic surgery (MMS) is a more effective treatment modality for tumors located in cosmetically and functionally important areas of the head and neck. We present a 56-years-old male patient with a large fungating eccrine tumor on the left axilla with ipsilateral nodal involvement on histomorphological grounds supported with immunohistochemical studies.

Porocarcinoma: Clinical and Histological Features, Immunohistochemistry and Outcomes: A Systematic Review

Porocarcinoma (PC) is a rare adnexal tumor, mainly found in the elderly. The tumor arises from the acrosyringium of eccrine sweat glands. The risk of lymph node and distant metastasis is high. Differential diagnosis with squamous cell carcinoma is difficult, although NUT expression and YAP1 fusion products can be very useful for diagnosis. Currently, wide local excision is the main surgical treatment, although Mohs micrographic surgery is promising. To date, there is no consensus regarding the role of sentinel lymph node biopsy and consequential lymph node dissection. No guidelines exist for radiotherapy, which is mostly performed based on tumor characteristics and excision margins. Only a few studies report systemic treatment for advanced PC, although therapy with pembrolizumab and EGFR inhibitors show promise. In this review, we discuss epidemiology, clinical features, histopathological features, immunohistochemistry and fusion products, surgical management and survival outcomes according to stage, surgical management, radiotherapy and systemic therapy.

Eccrine Porocarcinoma: Clinical and Histopathological Study of 14 Patients with Special Emphasis on Sentinel Lymph Node Biopsy

Eccrine porocarcinoma is a rare skin adnexal tumour that affects elderly people. Most eccrine porocarcinomas are stage I or II according to the American Joint Committee on Cancer. The prognosis is good in early stages, but worsens when advanced. Since information on the use of sentinel lymph node biopsy in these patients is scarce, this study examined the records of all patients with eccrine porocarcinoma treated at Helsinki University Hospital during a 17-year period and focused on sentinel lymph node biopsy patients. The study identified 14 patients (9 male, 5 female). There were 2 metastases to the lymph nodes and 2 recurrences at initial referral to our institution. All primary tumours had wide local excision and 6 patients also had sentinel lymph node biopsy, of whom none had positive lymph nodes. There were no new metastases or recurrences during follow-up. Three patients died of causes other than eccrine porocarcinoma. When comparing the wide local excision only and wide local excision with sentinel lymph node biopsy groups, no parameters reached statistical significance. The decision process of the multidisciplinary tumour board meeting on whether to perform sentinel lymph node biopsy was not clear, perhaps due to the limited knowledge of eccrine porocarcinoma. Further studies and international collaboration are warranted.

Epidemiology of porocarcinoma in England 2013-2018: a population-based registry study

BACKGROUND

Porocarcinoma (PC) is a cutaneous malignancy that differentiates towards (possibly arises from) the sweat ducts and glands. Lack of histological diagnostic markers makes clinical and pathological diagnosis complex. The limited data available suggest the incidence is increasing; however, this remains to be established in national epidemiological studies.

OBJECTIVES

To report the incidence, treatment and survival of patients with PC in England from 1 January 2013 to 31 December 2018 using national cancer registry data.

METHODS

PC diagnoses in England during 2013-2018 were identified from the National Disease Registration Service using morphology and behaviour codes. These were registered from routinely collected pathology reports and cancer outcomes and services datasets. The 2013 European age standardized incidence rates (EASRs), Kaplan-Meier all-cause survival and log-rank test were calculated.

RESULTS

In total, 738 tumours (396 in males and 342 in females) were diagnosed. The median age at diagnosis was 82 years old (interquartile range 74-88). The most frequently affected site were lower limbs (35.4%), followed by the face (16%). The majority of the cohort received surgical excision (73.0%). The Kaplan-Meier all-cause survival was 45.4% at 5 years, which was lower than in previous studies. The EASR for the whole population was 0.25 [95% confidence interval (CI) 0.23-0.27] per 100 000 person-years (PY)]. PC incidence rates in the East of England (EASR of 0.54, 95% CI 0.47-0.63 per 100 000 PY) were three times higher than the South West (EASR of 0.14, 95% CI 0.10-0.19 per 100 000 PY) where the regional rates were the lowest.

CONCLUSIONS

This study shows that there is large variation in the EASRs of PC across England. This may reflect differences in how PC is diagnosed and registered in different regions in England. These data support national assessment of the management of PC, which will inform future studies and guideline development.

Eccrine Porocarcinoma: A Review of the Literature

Eccrine porocarcinoma (EPC) constitutes a rare malignant adnexal tumor, which accounts for about 0.005-0.01% of all cutaneous malignancies. It may develop de novo or arise from an eccrine poroma, after a latency period of years or even decades. Accumulating data suggest that specific oncogenic drivers and signaling pathways may be implicated in its tumorigenesis, while recent data have demonstrated a high overall mutation rate attributed to UV exposure. Diagnosis may be challenging and should rely on the combination of clinical, dermoscopical, histopathological and immunohistochemical findings. The literature is controversial regarding tumor behavior and prognosis and, therefore, there is no consensus on its surgical management, utility of lymph-node biopsy and further adjuvant or systemic treatment. However, recent advances in tumorigenesis of EPC may aid in the development of novel treatment strategies, which could improve survival of advanced or metastatic disease, such as immunotherapy. This review presents an update of the epidemiology, pathogenesis and clinical presentation of EPC and summarizes current data on diagnostic evaluation and management of this rare cutaneous malignancy.

Porocarcinoma of the left arm: A report of a rare skin cancer case and literature review

Porocarcinoma is a rare type of skin cancer that develops from the intraepidermal ductal part of eccrine sweat glands. It can arise de novo or from poroma ground with high potential for locoregional metastatic spread, morbidity, and mortality. It mostly occurs in elderly patients.