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

A woman with mycosis fungoides, vitiligo, and a new hand nodule

A 70-year-old African American female with a history of stage IV mycosis fungoides in remission presented with a gradually enlarging, red, ulcerated nodule on her right dorsal hand. The lesion was biopsied, and it showed intraepidermal proliferation with cytologic atypia and increased vasculature in the papillary dermis. Immunohistochemical staining indicated a yes-associated protein 1 (YAP1) rearrangement, confirmed by RNA sequencing, revealing a YAP1::MAML2 (mastermind-like transcriptional coactivator 2) fusion. The lesion was diagnosed as an eccrine porocarcinoma (EPC). The occurrence of EPCs following radiotherapy or trauma has been documented. This case highlights the importance of considering EPCs in patients with extensive skin treatments and immunosuppression history.

Porocarcinoma with orbital metastasis, a case report with review of literature

We present a patient who presented with an orbital mass lesion which was a metastatic lesion from a porocarcinoma of the scalp with progressive deterioration of the patient.A 78-year-old male presented with functional decline and a rapidly growing scalp lesion of 3 months duration. In addition to the scalp lesion, Computed Tomography showed an incidental finding of a left lateral orbital wall tumour. Fine-needle aspiration of the two lesions revealed malignant cells with similar morphologies. Punch biopsy of the scalp lesion showed histological features suggestive of a porocarcinoma. Patient underwent palliative radiotherapy and immunotherapy and subsequently succumbed to the disease.

Enhanced Disease-Specific Survival Among Individuals With Malignant Adnexal Tumors of the Skin Treated With Mohs Surgery: A National Database Study

BACKGROUND

Malignant adnexal tumors of the skin are a rare group of tumors that can be locally aggressive and require surgical excision with strict margin control to achieve clearance. Given the rarity of these tumors, there is a limited understanding within the medical community regarding optimal treatment approaches.

OBJECTIVE

To examine surgical management trends and outcomes for patients diagnosed with cutaneous adnexal tumors from 2000 to 2020.

MATERIALS AND METHODS

The Surveillance, Epidemiology, and End Results database was queried to identify biopsy-proven cases of cutaneous adnexal tumors between 2000 and 2020. Clinical and disease characteristics were examined, and disease-specific survivals were compared between surgical approaches using Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

Mohs surgery demonstrated a significant increase in utilization from 2000 to 2020 (+447.1%) and improvements in disease-specific survival (mean 231.7 months; p < .001) compared with no surgery; wide local excision exhibited no improved disease-specific survival (227.7 months; p = .070). Multivariable Cox regression further highlighted that only Mohs surgery exhibited a reduced disease-specific mortality risk compared with no surgery (adjusted HR 0.49; p = .011).

CONCLUSION

Given the enhanced disease-specific survival coupled with tissue preservation strategies, Mohs surgery emerges as a promising surgical approach for the treatment of malignant adnexal tumors of the skin.

Ulcerated nodules with zosteriform distribution on the upper extremity

Eccrine porocarcinoma (EPC) is a rare skin adnexal malignancy with a high potential for metastases. The most common metastatic sites are the lymph nodes and lungs. CCutaneous metastasis is extremely rare, particularly the zosteriform variant, with fewer than 5 cases reported in the literature. Here, we report a unique case of EPC in a 71-year-old male, clinically presenting with multiple clusters of ulcerated nodules distributing as a zosteriform pattern throughout his upper left limb, along with draining lymphatic metastases and lymphedema.

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.

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 in the tempus of an elderly woman: A case report

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare skin tumor that mainly affects the elderly population. Tumors often present with slow growth and a good prognosis. EPCs are usually distinguished from other skin tumors using histopathology and immunohistochemistry. However, surgical management alone may be inadequate if the tumor has metastasized. However, currently, surgical resection is the most commonly used treatment modality.

CASE SUMMARY

A seventy-four-year-old woman presented with a slow-growing nodule in her left temporal area, with no obvious itching or pain, for more than four months. Histopathological examination showed small columnar and short spindle-shaped cells; thus, basal cell carcinoma was suspected. However, immunohistochemical analysis revealed the expression of cytokeratin 5/6, p63 protein, p16 protein, and Ki-67 antigen (40%), and EPC was taken into consideration. The skin biopsy was repeated, and hematoxylin and eosin staining revealed ductal differentiation in some cells. Finally, the patient was diagnosed with EPC, and Mohs micrographic surgery was performed. We adapted follow-up visits in a year and not found any recurrence of nodules.

CONCLUSION

This case report emphasizes the diagnosis and differentiation of EPC.

Spindle cell porocarcinoma with a novel YAP1::MAML3 fusion

Porocarcinomas are rare sweat gland cancers representing the malignant counterpart to benign poromas. Their diagnosis can be challenging, especially in the absence of an associated poroma or when the tumor is poorly differentiated. Since recurrent YAP1::MAML2 and YAP1::NUTM1 fusions have been identified in poroid tumors, molecular studies provide an opportunity to support the diagnosis in challenging cases. We describe a case of a female patient in her early 90s, with a polypoid mass of the hip. Histopathologically, there was a poorly differentiated malignant spindle cell tumor adjacent to a poroma. Because of the close association with a poroma and immunoreactivity for p40, a diagnosis of spindle cell porocarcinoma was rendered, which was further supported by YAP1 immunohistochemical studies. Antibodies targeting both the N-terminus and C-terminus confirmed YAP1 rearrangement in both the poroma and the spindle cell neoplasm. Subsequent targeted RNA sequencing revealed a YAP1::MAML3 gene fusion. MAML3 has previously not yet been reported as a YAP1 fusion partner in porocarcinoma. With the illustration of a rare spindle cell variant of porocarcinoma and the identification of a novel gene fusion, this case report expands the spectrum of morphologic and genomic aberrations associated with porocarcinoma.

Porocarcinoma in a palm reconstructed with a full thickness skin graft: A case report

BACKGROUND

Porocarcinoma is a rare type of skin cancer that originates from sweat gland tumors. It is an aggressive malignant skin cancer that is difficult to diagnose clinically owing to its rarity and similarity to squamous cell carcinoma (SCC).

CASE SUMMARY

This case involved a 92-year-old woman, a farmer by profession, presented with an exophytic and verrucous mass on her left palm that had formed 2 years prior and caused chronic pain and frequent bleeding. Initially, the patient was diagnosed with SCC using a punch biopsy; however, a repeat biopsy with additional immunohistochemical tests was performed for porocarcinoma. Ultimately, the patient was diagnosed with porocarcinoma and reconstruction was planned using a full-thickness skin graft. After treatment, the range of motion of the palm was preserved, and the aesthetic outcome was favorable. At 6 mo of follow-up, the patient was satisfied with the outcome.

CONCLUSION

Porocarcinoma is commonly misdiagnosed as SCC; therefore, clinicians should consider porocarcinomas when evaluating mass-like lesions on the hands.

Gene fusions in poroma, porocarcinoma and related adnexal skin tumours: An update

Poroma is a benign sweat gland tumour showing morphological features recapitulating the superficial portion of the eccrine sweat coil. A subset of poromas may transform into porocarcinoma, its malignant counterpart. Poroma and porocarcinoma are characterised by recurrent gene fusions involving YAP1, a transcriptional co-activator, which is controlled by the Hippo signalling pathway. The fusion genes frequently involve MAML2 and NUTM1, which are also rearranged in other cutaneous and extracutaneous neoplasms. We aimed to review the clinical, morphological and molecular features of this category of adnexal neoplasms with a special focus upon emerging differential diagnoses, and discuss how their systematic molecular characterisation may contribute to a standardisation of diagnosis, more accurate classification and, ultimately, refinement of their prognosis and therapeutic modalities.

Porocarcinoma of the Groin: A Case Report

Introduction

Porocarcinoma is a rare skin cancer that arises from the intraepidermal ducts of sweat glands. It is classically found in the 60-70-year-old age group, and lesions are most commonly reported on the head and neck or lower extremities.

Case Presentation

This case focuses on a 49-year-old man who presented to an outpatient dermatology clinic with a growing, painful nodule in his right groin. A shave biopsy was conducted and resulted in a diagnosis of a porocarcinoma.

Conclusion

Porocarcinoma is an extremely rare skin cancer that most commonly occurs on the head, neck, or lower extremities of 60-70-year-olds. This report details the interesting findings of a porocarcinoma in an unexpected location and age group and reviews pertinent literature.

Pazopanib elicits remarkable response in metastatic porocarcinoma: a functional precision medicine approach

Metastatic porocarcinomas (PCs) are vanishingly rare, highly aggressive skin adnexal tumors with mortality rates exceeding 70%. Their rarity has precluded the understanding of their disease pathogenesis, let alone the conduct of clinical trials to evaluate treatment strategies. There are no effective agents for unresectable PCs. Here, we successfully demonstrate how functional precision medicine was implemented in the clinic for a metastatic PC with no known systemic treatment options. Comprehensive genomic profiling of the tumor specimen did not yield any actionable genomic aberrations. However, ex vivo drug testing predicted pazopanib efficacy, and indeed, administration of pazopanib elicited remarkable clinicoradiological response. Pazopanib and its class of drugs should be evaluated for efficacy in other cases of PC, and the rationale for efficacy should be determined when PC tumor models become available. A functional precision medicine approach could be useful to derive effective treatment options for rare cancers.

Sweat Gland Carcinoma of the Head and Neck: Case Report and Literature Review

INTRODUCTION

The main aim of this article is to discuss and summarize the research advancements and the treatment methods for sweat gland carcinoma (SGC) based on 2 cases of SGC in our hospital and the related literature.

CASE REPORT

This article presents 2 patients with SGC who were treated in the China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases from 2007 to 2019. We analyzed the clinical features, therapies, and prognosis of the patients and searched for related literatures.

DISCUSSION

Two patients underwent extended resection for local lesions with no adjuvant radiotherapy. Neither local recurrence nor distant metastasis was detected during follow-up. Reviewing previous literature, the treatment of SGC includes surgical resection, radiotherapy, and chemotherapy. We have not found an effective treatment. The prognosis of SGC occurred in head and neck is relatively good compared with another primary-site location, primary surgical excision with safe resection margins and neck dissection is recommended.

Primary groin porocarcinoma in a 43-year-old man successfully managed by local excision: A case report and literature review

Porocarcinoma is a rare skin malignancy that should be suspected in patients with chronic skin lesions. Although it usually affects the elderly population in sun-exposed areas, it may be seen in younger populations and in nonexposed areas such as the groin.

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.

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.

Wide Local Excision for Eccrine Porocarcinoma of the Forearm

Eccrine porocarcinoma is a rare and aggressive cutaneous malignancy that develops in the seventh and eight decades of life. We present a 76-year-old male with eccrine porocarcinoma developing from a long standing previously benign lesion who underwent successful treatment with wide local excision. It can also develop de novo, presenting most commonly as a mass or nodule. Tissue biopsy with histopathology is required to confirm the diagnosis. Wide local excision is recommended for local disease. Radiation and chemotherapy can be used as adjuncts in advanced and metastatic disease. Given its rarity, there are no guidelines to direct therapy for locally advance or metastatic disease and for follow-up. Further studies are needed to better understand and guide management of this entity.

Radiotherapy of skin adnexal carcinoma

Skin adnexal carcinomas are rare skin cancer, developing from pilosebaceous, eccrine and apocrine unit. Treatment of localised tumours usually includes surgery and radiotherapy. Indications and modalities of radiotherapy depend on the pathological subtype with a lack of consensus for some histologies. This review summarises the place of radiotherapy in terms of indication, dose and fractionation, volumes to irradiate and discuss ongoing studies.

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.

Intracerebral and pituitary metastatic eccrine carcinoma: prolonged survival using stereotactic radiosurgery

PURPOSE

Eccrine gland carcinoma (EC) is a rare skin neoplasm that uncommonly spreads to the brain or pituitary gland. We describe the role of multiple stereotactic radiosurgery (SRS) procedures to manage recurrent brain metastases of this rare disease.

MATERIALS AND METHODS

Retrospective chart review was completed to obtain details for this report. The study was performed under IRB study on medical record only and was exempt from patient's consent.

RESULTS AND CONCLUSIONS

A 59-year-old female underwent surgical excision of a right parietal scalp EC. Over the next 13 years, the patient underwent initial fractionated whole brain radiation therapy after she developed multiple brain metastases followed by systemic chemotherapy for extracranial disease. Because of repeated development of new brain disease, three SRS procedures were performed to treat a total of 50 brain metastases and a pituitary metastasis (PM). The patient expired from progressive systemic cancer spread 13 years after her initial surgical excision. Due to the rarity of metastatic EC to the brain, no standard treatment paradigm has emerged. Using multimodality options that included local excision of the original skin tumor, followed by radiation, systemic chemotherapy, and three SRS procedures, long-term survival was possible in this unusual case.

Case report: Case report and literature review: Treatment of sweat gland carcinoma

Background

Sweat gland carcinoma (SGC) is a rare neoplasm originating from sweat glands. Surgical resection is the first choice for SGC treatment, and there is no consensus on other treatments for advanced SGC.

Methods and result

In this case report, we present a case of a female patient with advanced SGC who received surgery; radiotherapy; multiple lines of chemotherapy, which include docetaxel, nedaplatin, albumin-bound paclitaxel, and pemetrexed; and immunotherapy (camrelizumab). The survival time of this patient is 35 months. MRI tumor monitoring indicated that these treatments slowed the progression of the disease. The effectiveness of chemotherapy, radiotherapy, and immunotherapy should be tested for more patients with SGC in the future.

Conclusion

Although the patient's tumor was uncontrolled eventually, multiple treatments delayed tumor growth over a period of time, providing ideas for others when choosing regimens.

An Unusual Case of a Scrotal Porocarcinoma and Review of the Literature

ABSTRACT

Porocarcinomas are rare tumors derived from the acrosyringium and eccrine ducts, which most commonly occur on the lower extremities or head and neck region in older adults. Microscopically, they invariably demonstrate continuity with the epithelium, showing downgrowth of broad anastomosing bands with more infiltrative intradermal cords and nests of pleomorphic tumor cells with ductal lumina; an associated poroma may also be seen. We report an unusual case of a porocarcinoma arising on the scrotum of a 55-year-old man. Because of the extraordinary location and the presence of keratinizing squamous differentiation, distinction from a squamous cell carcinoma was particularly challenging. Close examination revealed the presence of a co-existing poroma, and immunohistochemistry revealed loss of YAP1 with diffuse nuclear expression of NUT in both the porocarcinoma and poroma components. This finding is particularly suggestive of a YAP1::NUTM1 fusion which has been reported to be highly specific for poroid neoplasms. Distinction of porocarcinoma from its mimics is important due to the frequent aggressive behavior of this neoplasm.

18F Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings in a Case of Metastatic Eccrine Porocarcinoma - An Extremely Rare Malignant Adnexal Tumor

Porocarcinoma is a rare malignant neoplasm of eccrine sweat glands representing 0.005 to 0.1% of all cutaneous tumors. As eccrine porocarcinoma carries a high risk of recurrence and metastases, early diagnosis and management are crucial to lower mortality rate. We present the case of porocarcinoma in a 69-years-old woman who underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for staging the disease. PET/CT showed metabolically active multiple cutaneous lesions and also picked up lymph nodal and distant metastases to lungs and breast accurately. PET/CT is useful for accurate staging of the disease and for treatment planning.

Eccrine porocarcinoma: an extremely rare cutaneous tumor from a radiological point of view - case report and review of the literature

Eccrine porocarcinoma is a rare type of skin neoplasm. It represents less than 0.01% of all epithelial cutaneous tumors. Early diagnosis is the only way to minimize the mortality rate, given its aggressive nature and the high rate of local recurrence and metastasis. Clinical diagnosis is challenging and the confirmation is histological. Few studies have been published about the radiological features of eccrine porocarcinoma. We report a case of a localized eccrine porocarcinoma along with ultrasound, MRI features, and a review of the literature to highlight the role of imaging in the diagnosis and treatment plan.

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)

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.

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.

Maligne Adnextumoren der Haut

Neoplasien der Hautadnexe (benigne oder maligne) können zum einen von den Talgdrüsen oder Haarfollikel ausgehen, zum andern auch eine Differenzierung Richtung ekkriner oder apokriner Schweißdrüsen zeigen. Auch Mischformen können vorkommen. Maligne Adnextumoren entstehen i. d. R. de novo. Dennoch ist auch die maligne Entartung einer vorbestehenden benignen Läsion möglich.

Maligne Adnextumoren der Haut sind im Vergleich zu anderen nicht-melanozytären Hauttumoren insgesamt eine eher seltene Entität. Jedoch zeigt sich, dass die Inzidenz von malignen Adnextumoren in den letzten Jahren zugenommen hat. Ähnlich wie bei anderen Hautkrebsarten sind auch bei malignen Adnextumoren das Alter, UV-Strahlung und Immunsuppression wichtige Risikofaktoren der Tumorgenese.

Da sich die Klinik sowohl von malignen als auch benignen Adnextumoren mit Ausnahme des Morbus Paget oftmals ähneln kann und wenig spezifisch ist, kommt der Histopathologie für die korrekte Diagnosestellung eine entscheidende Bedeutung zu.

Gemäß der Literatur sind die häufigsten malignen Adnextumore das Talgdrüsenkarzinom (23 %), der extramammäre Morbus Paget (19 %), das Hidradenokarzinom (15 %), das Porokarzinom (7 %) sowie das mikrozystische Adnexkarzinom (MAC) (5 %). Während manche Vertreter prognostisch mit einem Basalzellkarzinom vergleichbar sind (MAC), sind andere durchaus metastasierungsfähig vergleichbar den Plattenepithelkarzinomen (Talgdrüsenkarzinom, Porokarzinom). Andere Vertreter heben sich hier prognostisch besonders negativ ab mit hoher Lokalrezidivquote und Metastasierung, z. B. das Hidradenokarzinom.

Dieser Übersichtsartikel fokussiert sich auf diese 5 relativ häufigen Adnex-Malignome, die prognostisch auch die gegebene Streubreite wiedergeben und die Erfordernis einer den jeweiligen Besonderheiten geschuldeten klinischen Versorgung und Nachbetreuung unterstreichen.

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.

Imaging findings of malignant skin tumors: radiological-pathological correlation

Sometimes, radiologists encounter malignant skin tumors (MSTs) during image interpretation. As MSTs require different clinical management modalities for each histological subtype, accurate preoperative diagnosis is essential. The histological subtypes of MST can be easily assessed by visual inspection or biopsy. Therefore, the significant role of radiological imaging in MSTs is to evaluate the extent of local invasion, nodal involvement, and distant metastasis, and the histological estimation of MSTs by radiological imaging has not been reported until a few years ago. However, recent studies have revealed characteristic radiological features for differential diagnosis of MSTs, such as configuration, intratumoral homogeneity, signal intensity, cyst formation, and hemorrhage. Other important clinical data for determining the histological subtype of MST include age, gender, and site of occurrence. MSTs can be categorized as epidermal, melanocytic, adnexal, and mesenchymal tumors based on the origin and have distinctive characteristics. Hence, this review article was designed to describe the clinical and radiological features of MSTs.

Breast metastases of eccrine porocarcinoma

Eccrine porocarcinoma is a rare skin adnexal malignant neoplasm that may arise from a pre-existing benign eccrine poroma or without a predisposing factor. It is a highly invasive neoplasm and has a strong metastatic potential. The most frequently affected organs are the lymph nodes and rarely solid organs such as the liver, lungs and breast. We report a case of a woman with a history of surgically treated eccrine porocarcinoma that a year later presented with multiple lesions in both breasts and axillary lymphadenopathies. After a detailed imaging investigation, the diagnosis of metastatic lesions from porocarcinoma was made. To our knowledge, until the moment, only one case of breast metastasis of eccrine porocarcinoma has been reported in the literature.

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.

Treatment of Malignant Adnexal Tumors of the Skin: A 12-Year Perspective

Malignant adnexal cancers of the skin—extremely rare neoplasms—are mostly reported as non-symptomatic, slow-growing nodules. These carcinomas occur mainly in the middle-aged (50–60 years of age); they are mostly localized on the upper part of the body and are locally aggressive, infiltrate surrounding tissue, and metastasize to regional lymph nodes. The patients’ outcomes depend on multiple prognostic factors, including the size of the primary tumor and its mitotic count. Surgical resection of the primary tumor with or without regional lymph nodes is the treatment method of choice; however, due to aggressive tumor behavior, perioperative treatment may be considered. The role and efficacy of radiotherapy in the treatment of skin adnexal malignancies are not yet fully defined. Some authors suggest that adjuvant radiotherapy may be considered in locally advanced and regional disease. The aim of this study was to evaluate treatment outcomes and assess the efficacy of combined therapy in patients with adnexal malignancies. Our analysis covered all cases of cutaneous adnexal tumor patients diagnosed and provided with multidisciplinary treatment with surgery and radiotherapy since the beginning of 2009.

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.

TROP2 Expression in Sebaceous and Sweat Gland Carcinoma

Sebaceous carcinoma and sweat gland carcinoma (malignant tumors with apocrine and eccrine differentiation) are rare malignant skin adnexal tumors that differentiate toward sebaceous gland and eccrine and apocrine glands, respectively. Owing to the rarity of these carcinomas, standard treatments for advanced disease have not been established. Because the prognosis of patients with systemic metastasis is poor, a new treatment for these diseases is eagerly desired. Trophoblast cell surface antigen 2 (TROP2) and sacituzumab govitecan, an antibody–drug conjugate of TROP2, have attracted attention in the treatment of various solid tumors. In the current study, we immunohistochemically investigated TROP2 expression in 14 sebaceous carcinoma and 18 sweat gland carcinoma samples and found strong and relatively homogeneous TROP2 staining in both cancer types. The mean Histoscore, a semi-quantitative scoring ranging from 0 (negative) to 300, was 265.5 in sebaceous carcinoma and 260.0 in sweat gland carcinoma. These observations directly suggest that both sebaceous carcinoma and sweat gland carcinoma could be potentially treated with TROP2-targeted antibody–drug conjugates such as sacituzumab govitecan.

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.

Magnetic Resonance Imaging Characteristics of Poroma and Porocarcinoma

PURPOSE

The purpose of this study was to evaluate magnetic resonance (MR) imaging findings of poroma and porocarcinoma.

METHODS

Six patients (3 male, 3 female; age range, 40-84 years; mean age, 61 years) with histologically confirmed skin appendage tumors with apocrine and eccrine differentiation (2 poromas and 4 porocarcinomas) were enrolled. All patients underwent preoperative MR imaging and the MR images were retrospectively reviewed.

RESULTS

The configurations were classified as pedunculated solid in 5 lesions and subcutaneous cystic with mural nodules in 1. Well-demarcated deep tumor margins and smooth skin surfaces were observed in all 6 lesions, and peritumoral fat stranding was observed in 2. In all 5 pedunculated solid lesions, T2-hyperintense foci, T1 hyperintensity, and homogeneous solid components were observed within the lesions.

CONCLUSIONS

Poroma and porocarcinoma usually exhibited pedunculated solid homogeneous lesion. Intratumoral T2-hyperintense foci and T1 hyperintensity were observed in pedunculated solid lesions.

Management of brain metastasis from eccrine porocarcinoma: illustrative case

BACKGROUND

Eccrine porocarcinoma (EP) is a rare malignant skin neoplasm, and there are still many unknowns regarding its natural history and treatment. Due to its scarcity, associated brain metastasis is a far rarer condition.

OBSERVATIONS

A 71-year-old-woman with a history of EP was diagnosed with brain metastasis. In her clinical course, the patient underwent tumor removal surgery twice and Gamma Knife radiosurgery (GKRS) four times. The tumor showed a good response to radiotherapy. The histopathological findings of the brain tumor were consistent with those of the primary skin tumor.

LESSONS

There are only a few case reports referring to the detailed treatment, especially with GKRS, of brain metastasis from EP. Few reports have presented a detailed histopathological comparison between the primary skin lesion and the metastatic brain lesion. Herein, the authors have described the clinical course, histological features, and results of multidisciplinary treatment for brain metastasis of EP.

[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.

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.