Gene expression profiling in porocarcinoma indicates heterogeneous tumor development and substantiates poromas as precursor lesions.

BACKGROUND AND OBJECTIVES: Malignant sweat gland tumors are rare, with the most common being eccrine porocarcinoma (EP). Approximately 18% of benign eccrine poroma (EPO) transit to EP. Previous research has provided first insights into the mutational landscape of EP. However, only few studies have performed gene expression analyses. This leaves a gap in the understanding of EP biology and potential drivers of malignant transformation from EPO to EP. METHODS: Transcriptome profiling of 23 samples of primary EP and normal skin (NS). Findings from the EP samples were then tested in 17 samples of EPO. RESULTS: Transcriptome profiling revealed diversity in gene expression and indicated biologically heterogeneous sub-entities as well as widespread gene downregulation in EP. Downregulated genes included CD74, NDGR1, SRRM2, CDC42, ANXA2, KFL9 and NOP53. Expression levels of CD74, NDGR1, SRRM2, ANXA2, and NOP53 showed a stepwise-reduction in expression from NS via EPO to EP, thus supporting the hypothesis that EPO represents a transitional state in EP development. CONCLUSIONS: We demonstrated that EP is molecularly complex and that evolutionary trajectories correspond to tumor initiation and progression. Our results provide further evidence implicating the p53 axis and the EGFR pathway. Larger samples are warranted to confirm our findings.

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.

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.

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

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

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.

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.

Oestrogen Receptor Positive Metastatic Eccrine Porocarcinoma: A Case Report and Review of Anti-Oestrogen Therapy in Rare Cancers.

Introduction: Rare cancers, in aggregate, represent a significant burden of disease in oncology and remain therapeutically challenging to manage due to a lack of clinical trials. Eccrine porocarcinoma is a rare cutaneous sweat-gland malignancy for which there remains no standard approach to metastatic disease. Case Presentation: We describe a patient diagnosed with metastatic disease, confirmed on bone biopsy; pathological analysis further revealed this was oestrogen receptor positive. She was commenced on the aromatase inhibitor letrozole, and denosumab, and showed a significant clinical and radiological response on bone scan within 7 months. At the time of report, over 2 years since commencing letrozole, she remains well with no evidence of progression. Conclusion: Our experience adds to the literature suggesting anti-oestrogen therapy can have significant benefit in patients with ER-positive non-breast cancer and is in keeping with increasing interest in therapies agnostic to site of origin but guided by expression/mutation of oncogenic drivers.

No detectable truncating mutations in large T antigen (LT-Ag) sequence of Merkel cell polyomavirus (MCPyV) DNA obtained from porocarcinomas.

Merkel cell polyomavirus (MCPyV) is associated with Merkel cell carcinoma (MCC). In tumor cells the MCPyV large T antigen (LT-Ag) is frequently found truncated and this is considered a major tumor-specific signature. The role of MCPyV in other, non-MCC tumours, is little known. Viral DNA and/or tumour-specific mutations have been sometimes detected in different tumours, but such data are not unequivocal and the involvement of the virus in the tumorigenesis is not clear. In a previous study, we demonstrated a significantly higher prevalence of MCPyV DNA in formalin fixed paraffin embedded (FFPE) porocarcinoma tissues compared to the normal skin. In the present study, we investigated the presence of truncating mutations in MCPyV LT-Ag coding region in porocarcinoma specimens. Using several overlapped PCR primer pairs, the complete LT-Ag sequence from two biopsies were obtained. No truncating mutations were detected. The lack of truncating mutations in LT-Ag sequence does not seem to support the role of MCPyV in porocarcinoma oncogenesis. However, an oncogenetic mechanism, different from that proposed for MCC and not associated with the LT-Ag mutations/deletions, cannot be excluded. Further studies of more sequences coding for LT-Ag would be needed to verify this hypothesis.

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.

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.

Standardized surgical strategy for the treatment of preauricular sinus to reduce recurrence.

BACKGROUND: Preauricular sinus (PAS) is a common congenital anomaly, and complete excision is recommended to prevent recurrence. However, PAS has a high recurrence rate as a result of incomplete removal due to the high variability of the sinus ramifications, making its treatment challenging. In this study, we standardized the surgical procedure to reduce the complications and recurrence rate and compared the postoperative results between the non-standardized and the standardized groups. METHODS: This retrospective study included 97 patients (120 ears) who had undergone PAS excision by a single surgeon between October 2014 and September 2022 and underwent at least 6 months of follow-up. After October 2018, all patients were treated using the standardized method, which comprised the use of magnifying glasses, exploration with a lacrimal probe, the use of methylene blue staining, and excision of a piece of surrounding normal tissue and related cartilage in continuity with the specimen. There were 38 patients (45 ears) in the non-standardized group and 59 patients (75 ears) in the standardized group. RESULTS: Recurrence was observed in six of 120 ears, indicating an overall recurrence rate of 5.0%. Recurrence occurred in five ears (11.1%) in the non-standardized group and one ear (1.3%) in the standardized group. The standardized group had a significantly lower recurrence rate (p= 0.027) than the non-standardized group. CONCLUSION: We defined a standardized sinectomy protocol and used it for the surgical treatment of PAS. With this standardized method, we were able to reduce the rates of complications and recurrence without the use of a long incision.

Concurrent presentation of porocarcinoma and basal cell carcinoma arising on a capillary malformation: a case report.

Porocarcinoma (PC) and basal cell carcinoma (BCC) are distinct skin cancers. Few studies have documented the occurrence of two concurrent types of skin cancers, and to the best of our knowledge, this represents the inaugural report of such a coexisting lesion arising from a capillary malformation. Herein, we report a case of concurrent PC and BCC presenting with capillary malformation. A 93-year-old woman visited our hospital with a protruding mass in her right nasal ala that appeared as a capillary malformation. A biopsy was performed on the skin lesion, and BCC was diagnosed. A wide excision was performed. Permanent biopsy revealed that the skin lesion was a PC with basal cells and squamous differentiation. The safety margin of the deep tissue margin was < 0.1 cm; however, considering the advanced age of the patient, further excision was deemed to not possess any benefits. This case illustrates the importance of recognizing the possibility of multiple skin cancers, even in patients with benign lesions such as capillary malformations. The rarity of this presentation highlights the importance of thorough investigation and histopathological examination of skin lesions in guiding appropriate surgical excision.

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.

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 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.

A patient with porocarcinoma of the lower extremity and lung metastasis: a rare case report.

Background: Porocarcinoma is a rare cancer of the developing sweat glands. It often occurs in older adults and frequently affects the head, neck, and extremities. We report a rare case of metastatic porocarcinoma with intriguing approach of the diagnosis and management due to limited resource setting. Case Report: A 60-year-old man with a history of type 2 diabetes mellitus presented with nodules on the left foot with no palpable lymph node. A chest radiograph revealed multiple coin lesions and histopathological findings were suggestive for porocarcinoma. We assessed the case as a metastatic porocarcinoma in a patient with uncontrolled type 2 diabetes mellitus. Surgery was performed in the initial phase of treatment, consisting of below-knee amputation. The patient refused the planned chemotherapy in the referral hospital and then underwent other modalities of palliative care. He passed away eleven months after the initial diagnosis. Conclusions: Metastatic porocarcinoma is a rare oncological case with a challenging approach of the diagnosis and management. High awareness of clinical clues in rare cancer is needed for early diagnosis and prompt treatment, especially in limited resource settings.

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.

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.