Factors in the surgical management of primary eccrine porocarcinoma: prognostic histological factors can guide the surgical procedure

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: Pathogenesis, New Diagnostic Tools and Association with Porocarcinoma-A Review

Eccrine poroma (EP) is a relatively rare benign adnexal neoplasm that usually affects elderly patients. Its pathogenesis is still under investigation, but recent gene studies have revealed gene fusions as key incidences resulting in oncogenetic pathways. It often presents as a solitary, firm papule, mostly asymptomatic, located on the soles or palms. Due to its clinical and dermoscopic variability, it is characterized as the great imitator. We performed a literature review, aiming to summarize current data on the pathogenetic mechanisms, new dermoscopic features, and novel diagnostic tools that may aid in early diagnosis and proper management of this rare adnexal tumor. Furthermore, we reviewed the possible pathogenetic associations between EP and its malignant counterpart, namely eccrine porocarcinoma. This systematic approach may aid in understanding the pathogenetic mechanisms and how to use novel histopathologic markers and imaging methods to overcome the diagnostic dilemma of this rare tumor.

Porocarcinoma Concurrent with Psoriasis Vulgaris: The First Report

Psoriasis is a common chronical inflammatory skin disease with a prevalence of 2%-4% worldwide. In contrast, porocarcinoma is a relatively rare cutaneous neoplasm and an associated localization of both lesions is rare. Here, we describe the first case of porocarcinoma in a patient with psoriasis. A 71-year-old Japanese man was referred to our clinic for evaluation of nodule within a keratotic plaque of 20-years history on his leg. Histopathological examination showed that the plaque revealed acanthosis with regular elongation of rete ridges, agranulosis and the presence of Munro microabscesses. In contrast, massive proliferation of atypical poroid cells and a few cuticular cells in the dermis were seen in the nodule. We speculated that it is likely the porocarcinoma was caused by the elevated risk of skin cancer due to chronic inflammatory process of psoriasis itself in our patient.

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.

Eccrine Porocarcinoma of Dorsum of Nose: A Rare Case Report

Eccrine porocarcinoma (EPC) is an uncommon malignant tumor derived from the eccrine sweat glands. Because of its various pathological features, it is often confused with other malignant cutaneous tumors. We present a case of 78-year- old female having ulcerative lesion over external nasal pyramid. Biopsy suggested of squamous cell carcinoma. Tumor was excised and reconstruction was done using paramedian forehead flap. Post operative Histopathological Examination (HPE) suggested of eccrine porocarcinoma.

Intraabdominal dissemination of porocarcinoma; A case report

Introduction

Porocarcinoma is a rare malignancy of dermal sweat glands commonly diagnosed in the seventh decade of life. It frequently evolves from a de novo benign poroma. These tumors present as a mass/nodule, ulcer, papule, or wart. Difficult to differentiate from other cutaneous lesions. Intraperitoneal invasion is scantly reported in the literature.

Case presentation

The authors present a case of a fifty-year-old female patient with a rare cancer of the dermal sweat glands in an unusual location and infiltration into the abdominal cavity, leading to intraperitoneal seedlings.

Discussion

Tumors of the sweat gland are rare and difficult to diagnose, often misdiagnosed as granuloma, squamous cell tumors, or warts. Surgical excision and Mohs micrographic surgery are mainstay treatment modalities in the early stages. Our patient was managed elsewhere with a diagnosis of granuloma. She was referred with a recurrence of the abdominal lesion. An appropriate diagnosis of porocarcinoma was made while she had an extensive intraperitoneal invasion and seedlings. We postulate that the previous abdominal incision had disseminated porocarcinoma cells into the abdominal cavity, causing extensive intraperitoneal dissemination.

Conclusion

Because it is rare and difficult to diagnose, there is a considerable knowledge gap in the early accurate diagnosis and appropriate management of porocarcinoma. This causes a delay in establishing a diagnosis and profoundly impacts treatment outcomes.

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Eccrine porocarcinoma is a rare diagnosis of cutaneous malignancy.

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Early diagnosis and appropriate surgical treatment are the cornerstones of improving survival.

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It is often misdiagnosed as granuloma, squamous cell carcinoma, or viral warts.

YAP1-NUTM1 Gene Fusion in Eccrine Porocarcinoma with Late Metastatic Recurrence: A Case Report

Abstract is missing (Short communication)

Head and Neck Porocarcinoma: SEER Analysis of Epidemiology and Survival

Porocarcinoma is a rare malignant adnexal tumor. Little is known about the location of the disease in the head and neck. Our aim is to offer the largest analysis of demographic, pathological, and treatment patterns of head and neck porocarcinoma in comparison with other locations of the neoplasm from an epidemiologically representative cohort. Method: The Surveillance, Epidemiology, and End Results program of the National Cancer Institute was searched for all cases of porocarcinomas diagnosed between 2000 and 2018. This database is considered representative of the US population. Demographic, pathological, and treatment variables were compared between the head and neck and other regions. Overall and disease-specific survival was calculated and compared between groups. Results: 563 porocarcinomas were identified, with 172 in the head and neck. The mean age was 66.4 years. Males were more affected in the head and neck. Regional and distant invasion rates were low (2.9 and 2.3%, respectively). Local excision and Mohs surgery were the most frequent therapies. Five-year overall survival was 74.8%. Five-year disease-specific survival was 97%. Conclusions: Head and neck porocarcinoma affects more males than females. Regional or distant metastatic rates are low and overestimated in previous literature. Disease-specific mortality is low. Surgery remains the mainstay of treatment.

UV-induced local immunosuppression in the tumour microenvironment of eccrine porocarcinoma and poroma

Eccrine porocarcinoma (EPC) is a rare malignant adnexal tumour of the skin. Part of EPCs develop from their benign counterpart, poroma (EP), with chronic light exposure and immunosuppression hypothesized to play a role in the malignant transformation. However, the impact of chronic light exposure on the microenvironment of EPCs and EPs has not been investigated yet. Although the clinical relevance of tumour infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) has been established in various tumours, their distribution and significance in EPCs and EPs is still poorly understood. We characterized the distribution of TILs and TLSs using CD3, CD4, CD8, CD20 immunohistochemistry in a cohort of 10 EPCs and 49 EPs. We then classified our samples using solar-elastosis grading, analyzing the influence of ultraviolet (UV) damage on TIL density. A negative correlation between UV damage and TIL density was observed (CD4 r = −0.286, p = 0.04. CD8 r = −0.305, p = 0.033). No significant difference in TIL density was found between EPCs and EPs. TLS was scarse with the presence rate 10% in EPCs and 8.3% in EPs. The results suggest that UV has an immunosuppressive effect on the microenvironment of EPCs and EPs.

Porocarcinoma - a review

From the first report in 1969 to the present day, diagnosis of eccrine porocarcinoma, also known simply as porocarcinoma (PC), remains a challenge. This review presents a concise update of the history, pathogenesis, epidemiology, diagnosis, management and prognosis of this rare sweat gland neoplasm. It differentiates towards the intraepidermal spiral ducts in the eccrine gland, is more common in those over 60 years and often affects the head, neck and lower extremities. PC presents as a dome shaped papule, plaque or nodule growing over weeks to months. The exact incidence is unknown but appears to be rising. Diagnosis is difficult because of variable presentations and similar clinical and histological features to cutaneous squamous cell carcinoma. Management involves removal of the tumour, usually using wide local excision or Mohs micrographic surgery. Prognosis is poor with PC recurring after surgery in 35%. Given the lack of standardised protocols and risk profiles, further studies would help better the understanding of PC.

Porocarcinoma: a rare cause of lateral cervical tumor

Porocarcinoma is a rare tumor of the eccrine sweat glands that usually disseminates to the regional lymph nodes, but it can also develop distant metastasis. Case presentation: We report the case of a 67 year-old female patient who underwent wide surgical resection of a left cervical cutaneous tumor in a primary care center, for which the histology exam of the specimen was mixed basal cell and squamous cell carcinoma. She was referred to our hospital's oncology clinic and histologic re-evaluation changed the diagnosis to eccrine porocarcinoma (EPC). Computer-tomography (CT) revealed cervical lymphadenopathies for which the patient underwent 4 cycles of chemotherapy, without regression. She subsequently underwent a left upper anterior jugular lymphadenectomy (group IIa) with all nodes being negative and, three months later, she developed a unique adenopathy under the parotid gland that was excised and confirmed to be metastatic. Postoperative external radiotherapy was administered with a good outcome on CT scan. Nine months after her last surgery, the patient did not show any sign of recurrence or distant metastasis. Conclusion: EPC is a challenge, both diagnostically and therapeutically. In the absence of consensus regarding the indications and extent of lymphadenectomy and adjuvant therapy, patients with EPC should be referred to an experienced multidisciplinary team in a tertiary center.

Eccrine porocarcinoma: case report and review of the literature

Eccrine porocarcinoma is a rare skin cancer that originates from the acrosyringium of eccrine sweat glands. From the clinical point of view the differential diagnosis with other skin cancers such as basal cell carcinoma and squamous cell carcinoma it is often impossible, only the histopathologic features can lead to the definitive diagnosis. Eccrine porocarcinoma can arise from a previous poroma or de novo, it may recur after surgical excision and cause lymph node and visceral metastasis. There are no international guidelines for treatment or follow-up of patients. The aim of this work was to present a rare case of eccrine porocarcinoma of the scalp successfully treated in our clinic and to extrapolate from the international literature the main clinical and histopathological features of eccrine porocarcinoma and the various experiences regarding the types of treatment.

Merkel cell polyomavirus is a passenger virus in both poroma and porocarcinoma

BACKGROUND

Merkel cell polyomavirus (MCPyV) has been studied in several malignant and nonmalignant tissues. However, only in Merkel cell carcinoma (MCC) has the connection to tumorigenesis been established. Previously, eccrine porocarcinoma samples were shown to express MCPyV in the majority of samples. We aimed to examine MCPyV in porocarcinoma and poroma samples using MCC as the reference material.

METHODS

We analyzed 17 porocarcinoma and 50 poroma samples for the presence of MCPyV using LT antigen immunostaining and DNA detection methods. In addition, 180 MCC samples served as controls.

RESULTS

MCPyV LT antigen immunostaining was detected in 10% of poroma and 18% of porocarcinoma samples; on the other hand, it was present in 65% of MCC samples. MCPyV DNA was detected in only 10% of poroma and porocarcinoma samples compared with 96% of MCC samples. The viral DNA copy number in all MCPyV DNA-positive MCCs was at least 25 times higher than that in porocarcinoma or poroma samples with the highest MCPyV DNA-to-PTPRG ratio.

CONCLUSIONS

The low number of viral DNA copies in poroma and porocarcinoma samples, together with the negative LT expression of MCPyV DNA-positive tumors, indicates that MCPyV is simply a passenger virus rather than an oncogenic driver of porocarcinoma.

[Management of malignant adnexal neoplasms of the skin]

Malignant adnexal neoplasms of the skin are a heterogeneous group of rare malignancies with eccrine, apocrine, sebaceous and follicular differentiation. Essential clinical practice recommendations for the overall management of these cancers are presented. Moreover, specific evidence-based findings according to diagnosis, therapy and follow-up of porocarcinoma, sebaceous carcinoma and microcystic adnexcarcinoma will be explained.

Clear Cell Differentiation in Eccrine Porocarcinoma as a High-Risk Feature: Epidemiologic and Pathologic Features of Eccrine Porocarcinoma in a Single-Center Case Series

ABSTRACT

Eccrine porocarcinoma (EPC) is a rare sweat gland malignancy. Recognition of histologic features is challenging, and specific pathologic features correlate with risk of poor outcome. This single-center retrospective review and case series of 58 EPC cases from 2000 to 2016 elucidates epidemiologic and pathologic characteristics of EPC. Pathology slides from 52 cases were analyzed by a dermatopathologist for standardized variable characteristics, including previously determined high-risk features (HRF) associated with poor prognosis. The incidence of EPC increased over the study period with 3 times more cases diagnosed in the last 4 years than in the first 4 years. Most cases were in the elderly males (mean age 75 years), and 50% were located in the head and neck region. Although 38% of tumors exhibited one histologic HRF, only 10% exhibited more than one. Of the HRF, a greater tumor depth was associated with both increased age (P = 0.04) and clear cell differentiation (P = 0.02). This study elucidates epidemiologic and pathologic features of EPC and highlights how age and clear cell differentiation can be associated with greater tumor depth, although further research is needed to determine whether clear cell differentiation is associated with poor clinical outcome.

Intergluteal Cleft Eccrine Porocarcinoma with Metastasis to Inguinal Region and Lung: Case Report and Review of the Literature

Eccrine porocarcinoma (EPC) is an infrequent cutaneous neoplasm, and was described in 1963 by Pinkus and Mehregan. It is a rare type of skin tumor (0.005-0.01% of all skin tumors). Less than 300 cases have been described in the entire world medical literature. To our knowledge, no case of intergluteal cleft EPC has been reported in the literature in English and Spanish to date, so this would be the first reported case of such pathology. Metastatic EPC is less frequent, since only <10% of metastatic type have been reported and the rest as localized disease. The primary treatment of choice is surgical wide local excision of the tumor with histological confirmation of tumor-free margins. Prognosis is difficult to determine because of the rarity of EPC and the variations in natural history. There are no data to support the use of adjuvant chemotherapy or radiotherapy, and there are currently no agreed criteria to define patients at high risk of relapse. We present a 67-year-old man with intergluteal cleft eccrine tumor by biopsy. Metastasis to left inguinal region and lung was reported by contrasted abdominal and chest computed tomography. He started chemotherapy based on etoposide, vincristine, carboplatin. A review of pertinent literature is provided.

Occurrence of metastatic eccrine porocarcinoma in an immunosuppressed patient

Background

Eccrine porocarcinoma is a rare malignancy accounting for 0.005 to 0.01% of all cutaneous tumors. However, its etiology is not well established. Herein we are reporting the occurrence of metastatic porocarcinoma of the back in a patient with a history of multiple cutaneous malignancies and chronic immunosuppression.

Case presentation

A 79-year-old male with a history of long-term immunosuppressive therapy for left lung transplantation and multiple cutaneous malignancies including melanoma, presented with an enlargening plaque on the right upper back. Biopsy demonstrated an infiltrative epithelial tumor with aggressive histology and ductal formation. Immunohistochemical stains for p63, CK-5/6, and CEA were diffusely positive, while CK-7 and CK-20 were negative. A diagnosis of eccrine porocarcinoma was made. He underwent complete wide excision with negative margins of the right upper back in January 2018. In November 2018, he was found to have a right posterior shoulder mass, positive right axillary lymph nodes, superficial right upper back soft tissue masses and lymphangitic carcinomatosis involving the left lung. He was transitioned to comfort care and subsequently passed from metastatic disease in December 2018.

Conclusion

The occurrence of eccrine porocarcinoma in a patient on long term immunosuppressive therapy for lung transplantation suggests a possible role for chronic immunosuppression in the induction of a subset of eccrine porocarcinomas, as in other cutaneous malignancies.

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 on the Lateral Nose Wall: A Rare Case Report

Eccrine porocarcinoma (EPC) is an uncommon malignant tumor derived from the eccrine sweat glands. We present a case of EPC on the lateral nose wall, in which the tumor was excised, and the resultant defect was reconstructed using a nasolabial flap. A 66-year-old female was referred to the Department of Plastic and Reconstructive Surgery to receive treatment for a cutaneous tumor on her right lateral nose wall, which had been growing rapidly for 3 months. Histological analysis of a biopsy specimen of the tumor suggested that it was a squamous cell carcinoma. Surgical excision was performed with a 3-mm margin. The tumor was histologically diagnosed as an EPC. EPC exhibits various pathological features; therefore, it is often confused with other malignant cutaneous tumors. We consider that histologically examining surgical specimens obtained via total resection, rather than incisional biopsy specimens, is important for correctly diagnosing EPC.

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.

A synchronous incidence of eccrine porocarcinoma of the forearm and facial squamous cell carcinoma: A case report

INTRODUCTION

Cutaneous appendageal tumor can differentiate towards or arise from either pilosebaceous apparatus or the eccrine sweat glands. Appendageal tumors are relatively rare, their clinical appearance is non-specific, and the vast majority are not diagnosed until after excision. Eccrine porocarcinoma (EP), also known as malignant eccrine poroma is a rare adnexal tumor arising from the intraepithelial ductal parts of the sweat gland.

CASE PRESENTATION

We presented a 65-year-old, Asian, female with medical co-morbids, who came with both a facial squamous cell carcinoma and a long-standing lesion over her left forearm. Histopathological finding of the left forearm demonstrated eccrine porocarcinoma.

CONCLUSION

Mohs micrographic surgery is the mainstay treatment of cutaneous carcinoma. It is important to rule out associated syndromes in patient who present with multiple cutaneous appendageal tumors.

Adnexal Carcinomas Treated With Mohs Micrographic Surgery: A Comprehensive Review

BACKGROUND

Adnexal carcinomas (ACs) are rare cutaneous malignancies of sweat gland or pilosebaceous origin. Optimal treatment and metastatic potential of AC are poorly defined. Mohs micrographic surgery (MMS) has been increasingly used to treat AC.

OBJECTIVE

To review selected primary cutaneous AC and their treatment outcomes with MMS.

MATERIALS AND METHODS

Literature review using PubMed search for articles related to primary cutaneous ACs.

RESULTS

Sebaceous carcinoma treated with MMS recurred and metastasized in 6.4% and 3.7%, respectively. Primary cutaneous mucinous carcinoma treated with MMS recurred and metastasized in 9.6% and 6.4%, respectively. After MMS, 4.7% of microcystic AC recurred with no reported metastases. After MMS, recurrences and metastases of trichilemmal carcinoma or hidradenocarcinoma have not been reported. Two (4.2%) regional lymph node metastases but no distant metastases or local recurrences have been reported in eccrine porocarcinoma. Squamoid eccrine duct tumor, pilomatrix carcinoma, and spiradenocarcinoma treated with MMS are also reviewed.

CONCLUSION

The rarity of ACs and the lack of comparative data on treatment makes conclusive recommendations on treatment difficult. Recent large case series and reviews suggest MMS is a useful and possibly superior treatment for AC and should be considered if primary cutaneous disease is suspected.

Eosinophilic variant of eccrine porocarcinoma of the scalp: Case report and review of the literature

Porocarcinoma is a rare malignant neoplasm of the acrosyringium with metastatic potential that most commonly presents on the acral skin in older adults (mean age = 72 years). We present the case of a 43-year-old woman who developed a rapidly growing de novo porocarcinoma on the scalp with an unusual oncocytic appearance. The tumor consisted of benign eccrine poroma that arose from the epidermis and broad pushing borders with minimal cytological atypia but ample eosinophilic cytoplasm with numerous mitotic figures. Although some tumors may appear deceptively bland, the histologic recognition of pushing/infiltrative borders and mitotic figures are helpful to make the appropriate diagnosis of carcinoma. This lesion was treated with Mohs micrographic surgery and the patient remained free of recurrence after more than 2 years. It is important to recognize the eosinophilic variants of eccrine porocarcinoma because it can histologically mimic a squamous cell carcinoma.

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.

Treatment of Porocarcinoma With Mohs Micrographic Surgery: The Mayo Clinic Experience

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare malignant adnexal neoplasm with reported metastatic potential and undefined optimal treatment.

OBJECTIVE

This study reviews the clinical characteristics and outcomes of patients with EPC treated with Mohs micrographic surgery (MMS).

MATERIALS AND METHODS

The authors performed a retrospective chart review of patients with EPC treated by MMS at the Mayo Clinic from 1995 to 2013, recording patient demographics, tumor characteristics, MMS stages to clearance, follow-up, recurrence, metastasis, and mortality.

RESULTS

A total of 9 patients underwent MMS for EPC in 19 years. The average age was 64.2 years, with 6 males and 3 females. All patients were Caucasian. The head and lower extremity were the most common locations (44% each), with 1 on the forearm. Of the 9 tumors, 8 were located on the right side of the body. The mean preoperative tumor size and postoperative defect were 2.9 and 7.8 cm, respectively, when 2 outliers were excluded. An average of 1.3 MMS stages was required for clearance. The mean postoperative follow-up was 3.3 years (range: 1-60 months). No tumors treated with MMS recurred, metastasized, or led to disease-related mortality.

CONCLUSION

Mohs micrographic surgery seems to be a useful treatment modality for EPC. This is one of the largest single-center series of EPC treated with MMS.

Eccrine Porocarcinoma: Patient Characteristics, Clinical and Histopathologic Features, and Treatment in 7 Cases

Eccrine porocarcinoma is a rare, malignant cutaneous adnexal tumor that arises from the ducts of sweat glands. Found mainly in patients of advanced age, this tumor has diverse clinical presentations. Histology confirms the diagnosis, detects features relevant to prognosis, and guides treatment. Growth is slow, but the prognosis is poor if the tumor metastasizes to lymph nodes or visceral organs. We report 7 cases of eccrine porocarcinoma, describing patient characteristics, the clinical and histopathologic features of the tumors, and treatments used. Our observations were similar to those of other published case series. Given the lack of therapeutic algorithms or protocols for this carcinoma, we propose a decision-making schema based on our review of the literature and our experience with this case series. The algorithm centers on sentinel lymph node biopsy and histologic features.

Eccrine porocarcinoma of the vulva: a case report and review of the literature

Background

Malignant tumors arising from the vulva account for only 0.6 % of all cancers in female patients. The predominant histologic type, representing about 90 % of these malignancies, is squamous cell carcinoma. Eccrine porocarcinoma is a rare malignant tumor arising from sweat glands. The incidence of eccrine porocarcinoma is estimated at 0.005–0.01 % of all cutaneous tumors. To the best of our knowledge, only seven previous cases of vulvar eccrine porocarcinoma have been reported in the English-language literature. We present the case of a patient with eccrine porocarcinoma of the vulva, and we summarize the clinical features of this disease using seven previously reported cases.

Case presentation

A 54-year-old Japanese woman visited a local hospital complaining of fever and left vulvar pain for 2 months. An initial examination revealed a 1 × 1 cm, firm, ulcerative mass in the inner aspect of the left labium minorum. With a preoperative diagnosis of vulvar squamous cell carcinoma, we performed a radical local excision followed by bilateral inguinal lymphadenectomy. Histological examination showed eccrine porocarcinoma, stage IB (T1bN0M0). Radiation therapy with weekly cisplatin administration was then given as adjuvant therapy. One month after treatment was completed, computed tomography revealed multiple metastases in the bilateral lungs and in the sacral bone. The patient received three courses of chemotherapy (paclitaxel and carboplatin) and underwent palliative radiation therapy to the sacrum. She died of her disease 12 months after surgery.

Conclusions

We report the case of a patient with eccrine porocarcinoma of the vulva and summarize the clinical features and the treatment options of eccrine porocarcinoma from a few retrospective case reports. Although eccrine porocarcinoma is a rare disease, clinicians and pathologists should be aware of its clinical and histological features and its biological behavior.

Eccrine porocarcinoma with extensive cutaneous metastases

BACKGROUND

Eccrine porocarcinoma (EPC) is an uncommon malignant neoplasm that originates in the intraepidermal portion of the eccrine sweat duct. Although porocarcinoma is a slow-growing tumor, up to 20% of cases can metastasize to regional lymph nodes, thus increasing mortality.

METHODS

We describe the clinical and histopathological features and clinical course of three cases of extensive metastatic EPC diagnosed in our department over the last 10 years.

RESULTS

All three patients were women aged 89-96 years. They had numerous skin tumors on the left leg that were histologically and immunohistochemically diagnosed as metastatic EPC. Only one patient had a history of primary porocarcinoma, which had been excised 6 years earlier. The remaining two patients had a previous lesion diagnosed as squamous cell carcinoma. We treated the patients with palliative radiotherapy and/or chemotherapy. Only one patient is currently alive.

CONCLUSIONS

The cases of cutaneous and regional metastatic EPC we present occurred in elderly women with major involvement of the left leg. The third case is noteworthy, as the patient presented a long latency period before metastases appeared. Difficulties in the clinical diagnosis--and occasionally histological diagnosis--of primary EPC could delay more aggressive treatment, although optimal treatment does not always guarantee a good prognosis.

An unusual case of porocarcinoma arising on the scalp of a 22-year-old woman

Porocarcinoma is a rare malignant neoplasm that arises from the intraepidermal ductal portion of the eccrine sweat glands. This neoplasm most often presents in elderly individuals on the lower extremities. We present an unusual case of porocarcinoma arising on the scalp of a young patient. To the best of our knowledge, there have been fewer than 20 cases of porocarcinomas arising at this site reported in the literature.

A rare case of anal porocarcinoma treated by electrochemotherapy

We report the case of an old woman with an eccrine porocarcinoma unusually localized in the perianal area treated by electrochemotherapy, a new technique, emerging as a very effective local treatment of different skin metastases and selected primary tumors. Electrochemotherapy was performed taking into account patient wishes and refusal of demolitive surgery. The electrochemotherapy treatment was well tolerated by the patient, it gave an excellent clinical response and a complete clinical regression with no sphincter dysfunction and signs of relapse observed during follow-up. The case is of particular interest for the exceptional localization of porocarcinoma for the first time treated by electrochemotherapy in this area. Electrochemotherapy could be considered as an alternative option for selected cases of cutaneous tumors.

Mohs micrographic surgery for eccrine porocarcinoma: an update and review of the literature

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare malignancy of the eccrine sweat glands that is locally aggressive with a high propensity to metastasize. Most cases have been treated by wide local excision (WLE) with 20% local recurrence rate. There have been 20 cases of EPC treated with Mohs micrographic surgery (MMS) in the literature.

OBJECTIVE

To review the literature regarding the management of this aggressive tumor using MMS.

METHODS

A comprehensive literature review was conducted by searching the PubMed database using the keywords Mohs, porocarcinoma, malignant eccrine poroma, and eccrine neoplasms.

RESULTS

Most of the reported cases of EPC were treated by WLE, and only 20 cases were treated with MMS. Of the 20 EPC cases treated with MMS, there was only 1 nodal recurrence and no local recurrence. Other reported treatment modalities include radiation and excision with frozen sections. The authors report the second case of EPC on the temple, and the 21st case successfully treated with MMS.

CONCLUSION

Eccrine porocarcinoma is a rare neoplasm with potentially aggressive clinical behavior. In cases where tissue conservation is important, MMS should be considered.

A Case of Recurrent Eccrine Porocarcinoma with Regional Lymph Nodal Metastasis, Arising on a Bowen's Disease Patch

Eccrine carcinomas are very rare, comprising only less than 0.005 % of all cutaneous carcinomas, as reported by Goellner et al. (Cancer 56:1147-1162, 1985). We are reporting a case of recurrent eccrine porocarcinoma (EPC) with regional lymph nodal metastasis, which arose on a Bowen's disease patch. Wide local excision of the lesion with lymph node dissection and excision of the Bowen's disease was done.

[Eccrine porocarcinoma with Bowenoid changes: a challenging diagnosis of adnexal neoplasm]

Eccrine porocarcinoma is a rare malignant sweat gland tumor, representing less than 0.01% of all cutaneous neoplasms, with eccrin differentiation. Its acrosynringeal origin and physiopathology still remain discussed. The prognosis of this carcinoma is held to be poor with a significant risk of lymph node metastasis and local recurrence. Also, this not specific tumor can be a challenging histological diagnosis, in particular, in Bowenoid variant. We report a case of Bowenoid and keratinizing variant of eccrine porocarcinoma of the left ring finger with pejorative evolution and initial diagnosis of infiltrating squamous cell carcinoma arising in Bowen's disease. The knowledge of these patterns and identification of eccrine differentiation of the tumor are essential for the diagnosis and for adapted therapeutic care.