Successful Treatment of Eccrine Porocarcinoma Metastasized to a Cervical Lymph Node with CyberKnife Radiosurgery

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 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.

Primary Eccrine Porocarcinoma of the Breast: A Case Report and Review of Literature

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm, with less than 500 reported cases worldwide since it was first described in 1963. EPC tends to affect the elderly and most commonly affects the head and neck. The mainstay of EPC treatment is surgery, with lymphadenectomy in the case of nodal involvement or presence of unfavourable characteristics. No evidence exists to guide the use of adjuvant chemotherapy or radiation. EPC is prone to misdiagnosis given its multiple clinical and histopathological mimics, especially in uncommon sites of presentation such as the breast. Herein, we report the case of a 59-year-old woman who presented with a left breast skin lump. The biopsied specimen revealed an infiltrative carcinoma involving the dermis and epidermis with positive IHC staining for P63 and CK5/6 and negative staining for ER, PR, and HER2. The tumour was resected and diagnosed as EPC with atypical features as overlapping characteristics of squamous cell carcinoma (SCC) were detected on histopathological analysis. In our case, a simple mastectomy with broad margins and axillary lymph node dissection with adjuvant radiotherapy to a dose of 60 Gy failed to achieve loco-regional control with nodal recurrence occurring 4 months postsurgery-a testament to the aggressive course of this rare malignancy.

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

Adnexal tumors of the skin are a rare group of benign and malignant neoplasms that exhibit morphological differentiation toward one or more of the adnexal epithelium types present in normal skin. Tumors deriving from apocrine or eccrine glands are highly heterogeneous and represent various histological entities. Macroscopic and dermatoscopic features of these tumors are unspecific; therefore, a specialized pathological examination is required to correctly diagnose patients. Limited treatment guidelines of adnexal tumor cases are available; thus, therapy is still challenging. Patients should be referred to high-volume skin cancer centers to receive an appropriate multidisciplinary treatment, affecting their outcome. The purpose of this review is to summarize currently available data on pathogenesis, diagnosis, and treatment approach for apocrine and eccrine tumors.

Eccrine porocarcinoma of the head and neck: Meta-analysis of 120 cases

BACKGROUND

The aim of the study is to analyze potential prognostic factors and to evaluate therapy strategies regarding clinical outcome in patients with eccrine porocarcinoma (EPC) of the head and neck.

METHODS

One hundred and sixteen EPC cases from ninety studies and four authors' EPC cases were included in the meta-analysis.

RESULTS

At an average follow up of 20.48 months, the 3-year overall survival and regional recurrence rate were 70.3% and 19.0%, respectively. Patients without surgical treatment had a significantly worse 3-year overall survival. Mohs microscopic surgery led to significantly less occurrence of regional recurrences compared to wide excision. An ulcerating lesion, high mitotic activity, and lymphovascular invasion were significant prognostic factors.

CONCLUSION

Surgical resection is the cornerstone in the therapy of EPC and represents the therapeutic modality that offers the best chance of disease-free survival. Due to the high probability of recurrence, close follow-ups are strongly recommended.

Eccrine Porocarcinoma with Zosteriform Metastasis

Eccrine porocarcinoma is a rare malignant tumor that develops in the eccrine glands, appearing as a primary tumor, or by malignant transformation of an eccrine poroma. It is a carcinoma with high metastatic and recurrent potential; it has the same incidence in both sexes, and mainly affects the elderly. Its diagnosis, rather than clinical, is histological, and due to the rarity of the disease, it is a pathological challenge. There are no standardized treatment guidelines for porocarcinoma, but surgical resection with tumor-free margins is considered the basis of treatment, in addition to sentinel node biopsy under risk factors and individualization of each patient. For the metastatic form, chemotherapy and radiotherapy are the treatment of choice. Herein, we present the case of a man with eccrine porocarcinoma with extensive zosteriform skin metastasis and lymph node involvement, treated with chemotherapy and concomitant radiotherapy.

Metastatic porocarcinoma achieving complete radiological and clinical response with pembrolizumab

A 67-year-old woman presented in 2012 with a crusty nodule on the left lower limb. Histopathological examination at this time reported a poorly differentiated squamous cell carcinoma (SCC). Two years later, she underwent lymphadenectomy and radiotherapy due to unilateral inguinal and pelvic sidewall nodal metastases. The following year she required excision of two subcutaneous lesions, reported pathologically to be SCC metastases. Further imaging following cyberknife radiotherapy to new brain metastases demonstrated widespread metastatic visceral disease. Twelve cycles of carboplatin and capecitabine failed to halt disease progression. In February 2017, she commenced pembrolizumab, achieving an excellent response and currently has no clinical or radiological evidence of disease. Given the unusual behaviour of her cancer, a histopathological review was requested. The diagnosis was revised to that of porocarcinoma (PC). This represents the first documented case of PC treated with immunotherapy. As of March 2019, the patient remains free of disease.

Eccrine Porocarcinoma: New Insights and a Systematic Review of the Literature

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm with high potential for morbidity and mortality. Due to its rarity, there is a paucity of data profiling diagnosis, work-up, and management.

OBJECTIVE

To consolidate reported information on demographics, diagnostics, clinical behavior, treatment modalities, and patient outcomes in EPC to provide a reference tool to optimize diagnosis and management.

METHODS

A comprehensive PubMed search was performed from 1963 to November 2017 using PRISMA guidelines. This yielded 155 articles detailing 206 cases of porocarcinoma.

RESULTS

Eccrine porocarcinoma most often presents in elderly patients on the head and neck or lower limbs. Metastatic disease at presentation is not uncommon (22%). Primary tumor location is significantly correlated with presence of metastasis (p = .038). The most common treatment is excision followed by Mohs micrographic surgery (MMS), although the outcomes after MMS were superior to those after surgical excision.

CONCLUSION

This systematic review of individual patient data reveals that all patients should have a histological diagnosis with imaging considered for high-risk cases. Primary tumor location should also be considered in diagnostic and therapeutic decision-making. Although wide local excision (WLE) is currently the first-line treatment, MMS is becoming increasingly used, with evidence indicating improved outcomes as compared to those seen with WLE.

Porocarcinoma; presentation and management, a meta-analysis of 453 cases

BACKGROUND

porocarcinoma is a rare sort of skin cancer developing from sweat glands. Its clinical course and management are not well understood.

OBJECTIVES

the current meta-analysis is to address the presentation and management of porocarcinoma.

DATA SOURCES

Web of Science, PubMed, MEDLINE on OVID and Google scholar were searched for English-language studies published before December 1, 2016.

RESULTS

The review of literature revealed 453 cases. From which 222 (49%) cases were male and female were 231 (51%). The mean age was 67.57 years. The mean duration of presentation was 5.57 years ranging from 4 days to 60 years of age. The most common site of affection is the head and neck (39.9%) followed by lower extremity (33.9%). Mass and nodule are the most common modes of presentation. Metastasis occurred at presentation in 110 (31%) cases. The most common organ to which porocarcinoma metastizes is the nearby lymph node (57.7%).

CONCLUSIONS

Porocarcinoma is an aggressive skin cancer. Surgery is the main modality of treatment.

SYSTEMATIC REVIEW REGISTRATION NUMBER

reviewregistry233.