Porocarcinoma Research Articles

Case Report and Review of Eccrine Porocarcinoma in Skin of Color

Skin cancers are often misdiagnosed or diagnosed late in skin of color (Fitzpatrick types 4-6) resulting in increased morbidity and mortality. Rare skin cancers such as Eccrine Porocarcinoma (EPC), which accounts for 0.005% to 0.01% of all epidermal skin neoplasms, are even less likely to be accurately diagnosed in skin of color. Eccrine Porocarcinoma is often misdiagnosed as Squamous cell carcinoma (SCC), Basal Cell Carcinoma (BCC), melanoma, and seborrheic keratosis. The paucity of case reports of EPC in skin of color adds to the challenge of achieving accurate, timely diagnosis and treatment in this patient population. The purpose of this research is to review case reports of EPC documented in skin of color, highlighting salient clinical and histopathological characteristics of EPC, and to describe an additional case of EPC in skin of color that was initially misdiagnosed as seborrheic keratosis. Our search combined “eccrine porocarcinoma” and one of the following terms: “ethnic skin”, “skin of color”, “black”, “dark skin”, “African American”, “Indian”, “Native American”, “Asian”, “Hispanic”, “Indigenous Peoples”, “Middle Eastern” —as these tend to correspond with Fitzpatrick IV – VI types. Google scholar, PubMed, and Ovid MedLine Databases were used to search for articles. Case reports ranging from 1994 to present day were included in analysis.

The role of postoperative radiotherapy in eccrine porocarcinoma: a multidisciplinary systematic review.

Eccrine porocarcinoma (EPC) is a malignant adnexal tumor accounting for about 0.005% of skin tumors. The standard treatment of EPC is the complete surgical excision of the primary lesion and of the clinically involved lymph nodes. There is limited evidence regarding the role of radiotherapy (RT) in managing EPC after surgery. Therefore, the aim of this multidisciplinary systematic review is to analyze the available evidence about postoperative RT in the curative treatment of EPC. A systematic search strategy was launched trough the main scientific databases including PubMed, Scopus and Cochrane. An additional manual search and a chain citation were performed about potentially relevant papers. The key words used for the search included "eccrine porocarcinoma", "porocarcinoma", "radiotherapy", "radiation therapy", "adjuvant radiotherapy" and "postoperative radiotherapy". A total of 104 publications were identified and 14 papers were included in the final analysis. The only articles found on adjuvant RT in EPC were case reports published between 1996 and 2019. There was a slight female prevalence (57% female/43% male) with a mean age of 65 years (range 37-85). Head-and-neck region was the most frequently involved anatomical site followed by legs. Adjuvant radiotherapy after surgical removal of EPC could be considered in cases with positive or close margins and in cases with unfavorable histological features. In view of limited literature data and the rarity of EPC the best treatment sequence should always be discussed within the frame of a multidisciplinary setting. adjuvant radiotherapy after surgical removal of EPC could be considered in cases with positive or close margins and in cases with unfavorable histological features.

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

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. 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. 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. 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.

OP5: Eccrine Porocarcinoma: Experience of Sentinel Lymph Node Biopsy in Case Series of 14 Patients in Finland

INTRODUCTION: Eccrine porocarcinoma (EPC) is a rare malignant sweat gland tumour. Lymph node involvement is reported in 17-54% [1-3] of the cases. There are only few case series reporting the use of sentinel lymph node biopsy (SLNB) [2-4]. MATERIALS AND METHODS: This was a retrospective study including all patients treated with EPC in Helsinki University Hospital in 2000-2016. Medical records were reviewed in detail and all the histological samples re-evaluated. RESULTS: 14 patients were treated with EPC. At initial evaluation two patients had lymph node metastases and one tumour was a recurrence. SLNB was done in six patients. There were no positive sentinel lymph nodes. The primary tumour was treated with wide local excision. Two patients had lymph node dissections and one received adjuvant radiotherapy. There were no further recurrences or metastasis in follow-up (mean 8.4 years). Three patients died of unknown causes. At histological evaluation, the mean depth of invasion was 6.5 mm and the mean number of mitoses 3/mm2. There was no lymphovascular invasion. CONCLUSION: EPC might not behave as aggressively as previously reported. The role of SNLB in EPC warrants further studies.

Epidermodysplasia Verruciformis-Report of Familial Occurrence and a Rare Association with Eccrine Porocarcinoma.

Epidermodysplasia Verruciformis-Report of Familial Occurrence and a Rare Association with Eccrine Porocarcinoma.

Eccrine porocarcinoma at unusual location

Eccrine porocarcinoma at unusual location

Investigating new treatment strategies for eccrine porocarcinoma

British Journal of DermatologyVolume 185, Issue 6 p. e205-e205 Plain Language Summary Investigating new treatment strategies for eccrine porocarcinoma First published: 17 December 2021 https://doi.org/10.1111/bjd.20792AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Linked Article: Westphal et al. Br J Dermatol 2021; 185:1186–1199. Eccrine porocarcinoma is a rare skin cancer of the sweat gland. It affects 0·004% of people worldwide. Unfortunately, there are no effective treatment options available for patients with eccrine porocarcinoma that has spread throughout the body. To identify new treatment strategies it is important to first understand the underlying mechanisms of how this tumour develops and progresses within the body. We examined tumour tissue from a patient with eccrine porocarcinoma, who was referred to our clinic in Dresden, Germany. We observed numerous changes in the genetic code of the tumour cells that lead to an activation of cellular processes responsible for growth, survival and spread of the tumour cells within the human body. The cellular alterations that we saw in the tumour tissue of our patient were also detected in tumour tissue from 30 other patients with eccrine porocarcinoma. We took porocarcinoma cells from our patient and grew them in cell culture petri dishes in our laboratory. These cells were then treated with pharmaceutical drugs that interfere with the cellular processes we identified. Treatment with the drugs inhibited growth and resulted in the death of the porocarcinoma cells in our laboratory. Finally, we were able to treat our patient with porocarcinoma with the same drugs. The patient responded well to treatment. In this study, we investigated the underlying mechanisms of eccrine porocarcinoma tumour growth to develop new treatment options for patients with this rare disease. Volume185, Issue6December 2021Pages e205-e205 RelatedInformation

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.

A Case of Eccrine Porocarcinoma Accompanying Renal Cell Carcinoma

A Case of Eccrine Porocarcinoma Accompanying Renal Cell Carcinoma

High tumour mutational burden and EGFR/MAPK pathway activation are therapeutic targets in metastatic porocarcinoma.

Eccrine porocarcinoma (EPC) is a rare skin cancer arising from the eccrine sweat glands. Due to the lack of effective therapies, metastasis is associated with a high mortality rate. To investigate the drivers of EPC progression. We carried out genomic and transcriptomic profiling of metastatic EPC (mEPC), validation of the observed alterations in an EPC patient-derived cell line, confirmation of relevant observations in a large patient cohort of 30 tumour tissues, and successful treatment of a patient with mEPC under the identified treatment regimens. mEPC was characterized by a high tumour mutational burden (TMB) with an ultraviolet signature, widespread copy number alterations and gene expression changes that affected cancer-relevant cellular processes such as cell cycle regulation and proliferation, including a pathogenic TP53 (tumour protein 53) mutation, a copy number deletion in the CDKN2A (cyclin dependent kinase inhibitor 2A) region and a CTNND1/PAK1 [catenin delta 1/p21 (RAC1) activated kinase 1] gene fusion. The overexpression of EGFR (epidermal growth factor receptor), PAK1 and MAP2K1 (mitogen-activated protein kinase kinase 1; also known as MEK1) genes translated into strong protein expression and respective pathway activation in the tumour tissue. Furthermore, a patient-derived cell line was sensitive to EGFR and MEK inhibition, confirming the functional relevance of the pathway activation. Immunohistochemistry analyses in a large patient cohort showed the relevance of the observed changes to the pathogenesis of EPC. Our results indicate that mEPC should respond to immune or kinase inhibitor therapy. Indeed, the advanced disease of our index patient was controlled by EGFR-directed therapy and immune checkpoint inhibition for more than 2years. Molecular profiling demonstrated high TMB and EGFR/MAPK pathway activation to be novel therapeutic targets in mEPC.

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

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. 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. 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. 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.

Whole-exome sequencing in eccrine porocarcinoma indicates promising therapeutic strategies

Malignant sweat gland tumours are rare, with the most common form being Eccrine porocarcinoma (EP). To investigate the mutational landscape of EP, we performed whole-exome sequencing (WES) on 14 formalin-fixed paraffin-embedded samples of matched primary EP and healthy surrounding tissue. Mutational profiling revealed a high overall median mutation rate. This was attributed to signatures of mutational processes related to ultraviolet (UV) exposure, APOBEC enzyme dysregulation, and defective homologous double-strand break repair. All of these processes cause genomic instability and are implicated in carcinogenesis. Recurrent driving somatic alterations were detected in the EP candidate drivers TP53, FAT2, CACNA1S, and KMT2D. The analyses also identified copy number alterations and recurrent gains and losses in several chromosomal regions including that containing BRCA2, as well as deleterious alterations in multiple HRR components. In accordance with this reduced or even a complete loss of BRCA2 protein expression was detected in 50% of the investigated EP tumours. Our results implicate crucial oncogenic driver pathways and suggest that defective homologous double-strand break repair and the p53 pathway are involved in EP aetiology. Targeting of the p53 axis and PARP inhibition, and/or immunotherapy may represent promising treatment strategies.

An ulcerated exophytic tumour over the gluteal area- eccrine porocarcinoma in an immunocompetent female

Porocarcinoma is a very rare type of skin cancer arising from the eccrine sweat glands and is poorly understood. The exact pathogenesis is unknown. Clinical features are non-specific. It may present as a painless, slow growing mass or nodule, ulcer, plaque, swelling, wart, papule or naevus that increases in size over years to decades and may ulcerate or bleed upon trauma. They occur equally in both sexes and are most commonly found in the lower extremity. Though metastasis is rare, they are considered aggressive with high mortality rate. Diagnosis requires standard histopathological studies. Immunohistochemistry is useful in difficult cases. Treated early, eccrine porocarcinoma is curable by wide excision. The author reports the case of an eccrine porocarcinoma in the lower extremity of an elderly lady and a summary of its clinical, radiological and histological findings is illustrated.

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

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.

NUT Is a Specific Immunohistochemical Marker for the Diagnosis of YAP1-NUTM1-rearranged Cutaneous Poroid Neoplasms.

YAP1-NUTM1 fusion transcripts have been recently reported in poroma and porocarcinoma. NUTM1 translocation can be screened by nuclear protein in testis (NUT) immunohistochemistry in various malignancies, but its diagnostic performance has not been thoroughly validated on a large cohort of cutaneous epithelial neoplasms. We have evaluated NUT immunohistochemical expression in a large cohort encompassing 835 cases of various cutaneous epidermal or adnexal epithelial neoplasms. NUT expression was specific to eccrine poromas and porocarcinoma, with 32% of cases showing NUT expression. All other cutaneous tumors tested lacked NUT expression, including mimickers such as seborrheic keratosis, Bowen disease, basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, nodular hidradenoma, and all other adnexal tumors tested. Remarkably, NUT expression was more frequent in a distinct morphologic subgroup. Indeed, 93% of poroid hidradenoma (dermal/subcutaneous nodular poroma, 13/14) and 80% of poroid hidradenocarcinoma cases (malignant poroid hidradenoma, 4/5) showed NUT expression, in contrast to 17% and 11% of classic poroma (4/23) and porocarcinoma cases (4/35), respectively. RNA sequencing of 12 NUT-positive neoplasms further confirmed the presence of a YAP1-NUTM1 fusion transcript in all cases, and also an EMC7-NUTM1 gene fusion in a single case. In the setting of a cutaneous adnexal neoplasm, nuclear expression of NUT accurately and specifically diagnosed a specific subgroup of benign and malignant poroid tumors, all associated with a NUTM1 fusion, which frequently harbored a poroid hidradenoma morphology.

Extracalvarial Porocarcinoma- A Rare Case Report

Eccrine Porocarcinoma (EPC) is a very rare malignant neoplasm of skin. It usually emerges from the ductal parts of sweat glands. It is seen mostly between the age group of 60 to 80 years with a female preponderance. Several cases of EPC have been reported in medical literature till date. Though, it rarely presents with distant metastasis, still evidences of metastasis to organs like lung, retroperitoneum, breast, urinary bladder and ovaries have been reported. Conventionally, it arises de novo, and may develop on sites of long standing eccrine poroma. Several unusual sites like trunk, head, face, eyelids, upper limbs, and scrotum have been reported; though lower extremities are the most common site of origin. Locoregional recurrence and metastasis have also been reported. Histopathological documentation of mitoses, lymphovascular invasion and measurement of tumour depth predicts adverse prognosis in EPC. Earlier, eccrine adenocarcinoma or malignant eccrine poroma terminology were used. As far as clinical presentation is concerned, the EPC is usually symptomless to begin with, which further ulcerates and may become aching and irritable. From a clinicopathological perspective the importance of the tumour lies in its early correct diagnosis, awareness of the close differentials, adequate surgery and most importantly clearance of surgical margins and adjuvant radiotherapy are mandatory decisions to prevent the high local recurrence. The basis of management involves wide local excision with clear margin. The following case, a 42-year-old male presented with an ulcerated mass on the scalp, which on further evaluation was diagnosed as an EPC of the scalp after histopathologic confirmation. The patient was treated with local wide excision with clear margin and was referred for radiotherapy.

Diagnostic Pitfalls of Eccrine Porocarcinoma with Extensive Squamous Differentiation

Diagnostic Pitfalls of Eccrine Porocarcinoma with Extensive Squamous Differentiation

Carcinoma erysipeloides deriving from a metastatic eccrine porocarcinoma: A rare case report and brief review of the literature

Carcinoma erysipeloides deriving from a metastatic eccrine porocarcinoma: A rare case report and brief review of the literature

18126 Demographics and outcomes of eccrine porocarcinoma: Results from the National Cancer Database

Eccrine porocarcinoma (EP) is a rare type of skin malignancy arising from eccrine sweat glands. Owing to limited case-load, larger database studies are needed for the epidemiologic characterization and assessment of treatment outcomes of EP. The National Cancer Database (NCDB) was queried for all confirmed EP cases of the skin diagnosed between 2004 and 2015. Frequency functions, Kaplan-Meier and Cox regression models were used to analyze demographics, treatment, and survival. We identified 568 cases. The most common primary site was the lower limb and hip (33.1%) followed by the head and neck (28.9%). The average age of diagnosis was 62.1. Men and women were affected equally (P > .05). The most common treatment was surgery alone (91.8%). 61.9% of patients were diagnosed with AJCC stage I and 30.0% with stage II disease. 1.1% of patients had metastases at diagnosis. The sites of metastases were bone (50%), lung (40%), and brain (10%). The median tumor size was 25.5 millimeters (largest diameter). The 5-year and 10-year overall survivals (OS) were 68.7% and 53.3%, respectively. On univariate analysis, younger age, surgery, radiation, black race, and lower stages were associated with increased OS (P < .05). Trunk lesions were associated with decreased OS (5-year 58.5% and 10-year 41.2%). On multivariate analysis, older age (HR 1.067; P < .05) and tumors greater than 60 millimeters (largest diameter) (HR 2.8; P < .05) were associated with decreased OS. This study represents the largest cohort of eccrine porocarcinoma to our knowledge. More evidence is needed to create treatment guidelines for this rare condition.

16271 Eccrine porocarcinoma: A clinicopathologic analysis of 20 patients

Introduction: Eccrine porocarcinoma (EP) is a rare skin cancer arising from eccrine sweat glands. It mainly occurs in the elderly and has significant metastastic potential. Because of the rarity of the tumour, a standardized approach for diagnosis and management is lacking.