Poroma: a review of eccrine, apocrine, and malignant forms

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.

Porocarcinomas with PAK1/2/3 fusions: a series of 12 cases

AIMS

Porocarcinoma is a malignant sweat gland tumour differentiated toward the upper part of the sweat duct and may arise from the transformation of a preexisting benign poroma. In 2019, Sekine et al. demonstrated the presence of YAP1::MAML2 and YAP1::NUTM1 fusions in most poromas and porocarcinomas. Recently, our group identified PAK2-fusions in a subset of benign poromas. Herein we report a series of 12 porocarcinoma cases harbouring PAK1/2/3 fusions.

METHODS AND RESULTS

Five patients were male and the median age was 79 years (ranges: 59-95). Tumours were located on the trunk (n = 7), on the thigh (n = 3), neck (n = 1), or groin area (n = 1). Four patients developed distant metastases. Microscopically, seven cases harboured a benign poroma component and a malignant invasive part. Ductal formations were observed in all, while infundibular/horn cysts and cells with vacuolated cytoplasm were detected in seven and six tumours, respectively. In three cases, the invasive component consisted of a proliferation of elongated cells, some of which formed pseudovascular spaces, whereas the others harboured a predominant solid or trabecular growth pattern. Immunohistochemical staining for CEA and EMA confirmed the presence of ducts. Focal androgen receptor expression was detected in three specimens. Whole RNA sequencing evidenced LAMTOR1::PAK1 (n = 2), ZDHHC5::PAK1 (n = 2), DLG1::PAK2, CTDSP1::PAK1, CTNND1::PAK1, SSR1::PAK3, CTNNA1::PAK2, RNF13::PAK2, ROBO1::PAK2, and CD47::PAK2. Activating mutation of HRAS (G13V, n = 3, G13R, n = 1, Q61L, n = 2) was present in six cases.

CONCLUSION

Our study suggests that PAK1/2/3 fusions is the oncogenic driver of a subset of porocarcinomas lacking YAP1 rearrangement.

Eyelid Eccrine Poroma: A Case Report and Literature Review

Eccrine poroma is a rare benign adnexal tumor arising from intradermal cells of eccrine sweat ducts. At least two-thirds of eccrine poromas present on the extremities, most commonly on the palms and soles. They are scarcely found on the face; to date, only 11 cases of eyelid poromas have been reported in PubMed. Biopsy excision with a free margin is necessary to distinguish it from malignant lesions and avoid recurrence with possible transformation to porocarcinoma. We present the case of a 23-year-old male with a histopathological confirmation of poroma using staining with hematoxylin-eosin on the eyelid, previously clinically diagnosed with molluscum contagiosum. After four years, he has not experienced a recurrence.

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.

Detection of wildtype Merkel cell polyomavirus genomic sequence and VP1 transcription in a subset of Merkel cell carcinoma

AIMS

Merkel cell carcinoma (MCC) is frequently caused by the Merkel cell polyomavirus (MCPyV). Characteristic for these virus-positive (VP) MCC is MCPyV integration into the host genome and truncation of the viral oncogene Large T antigen (LT), with full-length LT expression considered as incompatible with MCC growth. Genetic analysis of a VP-MCC/trichoblastoma combined tumour demonstrated that virus-driven MCC can arise from an epithelial cell. Here we describe two further cases of VP-MCC combined with an adnexal tumour, i.e. one trichoblastoma and one poroma.

METHODS AND RESULTS

Whole-genome sequencing of MCC/trichoblastoma again provided evidence of a trichoblastoma-derived MCC. Although an MCC-typical LT-truncating mutation was detected, we could not determine an integration site and we additionally detected a wildtype sequence encoding full-length LT. Similarly, Sanger sequencing of the combined MCC/poroma revealed coding sequences for both truncated and full-length LT. Moreover, in situ RNA hybridization demonstrated expression of a late region mRNA encoding the viral capsid protein VP1 in both combined as well as in a few cases of pure MCC.

CONCLUSION

The data presented here suggest the presence of wildtype MCPyV genomes and VP1 transcription in a subset of MCC.

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.

The role of line-field confocal optical coherence tomography (LC-OCT) in the diagnosis of eccrine poroma: A case report

Poroma is skin cancer that arises from the sweat gland cells. Its diagnosis could be difficult. Line-field optical coherence tomography (LC-OCT) is a novel imaging technique that has shown promise in the diagnosis and monitoring of various skin conditions. We report a case of poroma diagnosed by LC-OCT.

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.

Challenges in the diagnosis and treatment of the malignant adnexal neoplasms of the head and neck

PURPOSE OF REVIEW

The current review is to present the current knowledge regarding epidemiology, diagnostics, and management of malignant adnexal neoplasms (MANs).

RECENT FINDINGS

Immunotherapy and gene-related therapies are still being developed as the methods of salvage treatment in advanced and disseminated cases: CACNA1S, ATP2A1, RYR1, and MYLK3, as well as p53 or the JAK/STAT pathways, may be therapeutic targets; the efficiency of talimogene laherparepvec and nivolumab is assessed.

SUMMARY

MANs are rare tumors, but due to the aging of population their incidence is increasing. Their clinical presentation is unspecific, which makes the diagnosis challenging. Histopathological assessment is difficult even for experienced pathologists. Mohs micrographic surgery or wide local excision are recommended to treat primary lesions. Adjuvant radiotherapy may be beneficial in case of insufficient or positive surgical margins, in nodal metastases, in selected types of MANs like sebaceous, trichilemmal, and pilomatrix carcinomas, and as the induction treatment in large tumors located in medically fragile or cosmetically important regions. The role of chemotherapy is not well defined; however, it is recommended in distant metastases. Immunotherapy can improve the prognosis in advanced stage of the disease.

[Translated article] Poroma: A Retrospective Series of 80 Patients at a Tertiary Care Hospital

BACKGROUND

Poroma is a benign, exclusively cutaneous, adnexal tumor with a predilection for palmoplantar skin.

OBJECTIVE

To analyze the clinical characteristics of poroma in our population.

MATERIAL AND METHODS

Retrospective study of patients diagnosed with poroma between 2002 and 2021. We conducted a chart review to record age; sex; number, location, and diameter of lesions; time since onset; clinical characteristics; suspected clinical diagnosis; resection margin status; recurrences; and follow-up duration. Categorical variables were compared using the Fisher exact test. Continuous variables were compared using the t test or the Mann-Whitney U test depending on whether they were normally or nonnormally distributed.

RESULTS

We studied 80 patients (31 women and 49 men) with a median (interquartile range [IQR]) age of 65.5 (29) years. Median time since onset of poroma was 12 (21) months. Median lesion diameter was 8 (7)mm, and none of the patients had multiple lesions. The lesions were located on the head and neck in 13 cases, the trunk in 13, the upper extremities in 11, and the lower extremities in 43. Twenty-three lesions (28.8%) were located at acral sites (5 on the palms and 18 on the soles). Women were more likely to have scalp lesions (P=.041). Acral lesions were more likely to be erythematous (P=.014). Five patients experienced local recurrence.

CONCLUSIONS

Although poromas are particularly common in acral locations (especially the feet), most of the lesions in our series (71.3%) were located elsewhere. Acral lesions were more likely to show the classic clinical features of erythema and exophytic growth.

YAP1::MAML2 fusions in poromatosis: A report of two patients

Poromatosis is a rare condition characterized by the development of multiple poromas, mainly reported in patients with a history of malignancy. Recently, frequent YAP1::MAML2 and YAP1::NUTM1 fusions have been described in poromas and porocarcinomas. To date, the molecular features of poromatosis have been investigated in one patient only, wherein the poromas harbored YAP1::MAML2 fusions. Herein, we present two additional cases of poromatosis with YAP1::MAML2 fusions. Case 1: An 81-year-old woman presented with nine papules on the scalp, trunk, and extremities persisting for a year. She had a history of breast cancer, with no information on the treatment. Seven papules were excised. Case 2: A 65-year-old woman presented with 21 lesions on her trunk and lower extremities persisting for 2 years. She had been diagnosed with breast cancer 11 years prior and had undergone partial mastectomy, radiotherapy, chemotherapy, and endocrine therapy. Four lesions were excised. All 11 lesions in both patients were histopathologically similar: anastomosing cords and strands extending from the epidermis, and poroid and cuticular cell proliferation with interspersed small ducts. The tumors showed diffuse nuclear expression of YAP1 N-terminus and loss of YAP1 C-terminus expression. No lesions showed NUT immunopositivity. Sanger sequencing identified YAP1::MAML2 fusions in the poromas of both patients.

Poroma: A Retrospective Series of 80 Patients at a Tertiary Care Hospital

BACKGROUND

Poroma is a benign, exclusively cutaneous, adnexal tumor with a predilection for palmoplantar skin.

OBJECTIVE

To analyze the clinical characteristics of poroma in our population.

MATERIAL AND METHODS

Retrospective study of patients diagnosed with poroma between 2002 and 2021. We conducted a chart review to record age; sex; number, location, and diameter of lesions; time since onset; clinical characteristics; suspected clinical diagnosis; resection margin status; recurrences; and follow-up duration. Categorical variables were compared using the Fisher exact test. Continuous variables were compared using the t test or the Mann-Whitney U test depending on whether they were normally or nonnormally distributed.

RESULTS

We studied 80 patients (31 women and 49 men) with a median (interquartile range [IQR]) age of 65.5 (29) years. Median time since onset of poroma was 12 (21) months. Median lesion diameter was 8(7)mm, and none of the patients had multiple lesions. The lesions were located on the head and neck in 13 cases, the trunk in 13, the upper extremities in 11, and the lower extremities in 43. Twenty-three lesions (28.8%) were located at acral sites (5 on the palms and 18 on the soles). Women were more likely to have scalp lesions (P=.041). Acral lesions were more likely to be erythematous (P=.014). Five patients experienced local recurrence.

CONCLUSIONS

Although poromas are particularly common in acral locations (especially the feet), most of the lesions in our series (71.3%) were located elsewhere. Acral lesions were more likely to show the classic clinical features of erythema and exophytic growth.

Pigmented eccrine poroma in an atypical location

Eccrine poroma is the term that includes benign neoplasms of the terminal duct of the eccrine sweat glands, which may clinically and dermoscopically resemble other melanoma and non-melanoma skin tumors. They are often located on the extremities (especially palms and soles), presenting as normochromic or erythematous papules and nodules, measuring up to 2 cm. Pigmented variants are uncommon, accounting for less than 20% of cases. This report describes a 37-year-old man who developed a large pigmented eccrine poroma on his right shoulder, causing diagnostic difficulty. Histopathological examination revealed a nodular neoplasm consisting of small, monomorphic, cuboidal cells, with ample, eosinophilic cytoplasm and well-defined borders, in addition to conspicuous intercellular bridges, with melanin deposits diffusely distributed inside them. The absence of cytological atypia, cellular pleomorphism, increased mitotic activity, and necrosis foci corroborated the diagnostic exclusion of porocarcinoma, which can develop from eccrine poroma.

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.

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.

Dermal Duct Tumor: A Diagnostic Dilemma

Poromas or poroid tumors are a group of rare, benign cutaneous neoplasms derived from the terminal eccrine or apocrine sweat gland duct. There are four poroma variants with overlapping features: dermal duct tumor (DDT), eccrine poroma, hidroacanthoma simplex, and poroid hidradenoma, of which DDT is the least common. Clinically, the variants have a nonspecific appearance and present as solitary dome-shaped papules, plaques, or nodules. They can be indistinguishable from each other and a multitude of differential diagnoses, necessitating a better understanding of the characteristics that make the diagnosis of poroid neoplasms. However, there remains a paucity of information on these lesions, especially DDTs, given their infrequent occurrence. Herein, we review the literature on DDTs with an emphasis on epidemiology, pathogenesis, clinical features, diagnosis, and management.

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.

Unusual Presentations of Eccrine Porocarcinomas

Eccrine porocarcinomas (EPCs) are rare tumours, albeit the most common malignant adnexal tumours of the skin. They can present with very heterogeneous clinical and dermoscopic features, rendering diagnosis limited to histopathological examination alone. We share 2 cases of EPCs, one of which arose in a patient with a prior diagnosis of cutaneous squamous cell carcinoma (SCC) and another whose EPC was likely a malignant transformation of an existing poroma. An occurrence of porocarcinoma after the diagnosis of SCC may suggest the possibility of unknown risk factors for both. Positivity to androgen, oestrogen, and epidermal growth factor receptors was seen in a proportion of porocarcinomas, and this may prompt further research on combination therapy between conventional treatment modalities with hormone receptor antagonists. Malignant change of a poroma may be a more common phenomenon than we would expect based on the current literature.

Eccrine poroma presented as spindle-shaped plaque: A case report

RATIONALE

Eccrine poroma, a benign cutaneous neoplasm originating from the intraepidermal portion of the eccrine sweat duct, is relatively common in clinical practice. Nevertheless, the 1 presenting as spindle-shaped plaque is extremely rare and easily misdiagnosed as seborrheic keratosis or other dermatoses. Thus, the current study demonstrates a case of eccrine poroma with unique clinical manifestation.

PATIENTS CONCERNS

A 47-year-old man presented with a spindle-shaped plaque on his left sole for 6 years.

DIAGNOSES

Based on the clinical and histopathological manifestations, diagnosis of eccrine poroma was established.

INTERVENTIONS

Surgical excision under local anesthesia was performed.

OUTCOMES

No recurrence or malignant transformation occurred within 6-month follow-up.

LESSONS

Eccrine poroma typically presents as a dome-shaped nodule on palm or sole. But this case reminded us the lesion presenting as a spindle-shaped plaque on sole can not rule out the possibility of eccrine poroma.

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

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

Eccrine Porocarcinoma: A Challenging Diagnostic and Therapeutic Tumoral Entity

Eccrine porocarcinoma is a rare malignant cutaneous tumor with high rates of extracutaneous spread, and its diagnosis and management can be quite challenging. This is a case of an 82-year-old woman presenting with an asymptomatic and chronic pubic skin lesion for whom the work-up required many investigations and procedures to confirm the diagnosis of metastatic eccrine porocarcinoma. Indeed, the patient underwent a wide local excision of the skin lesion, imaging with an FDG-PET scan, a colonoscopy, and two inguinal node dissections. As illustrated in this case, surgery should always be considered to achieve disease remission. Other treatments such as chemotherapy and radiotherapy have also been reported in the literature without clear standard guidelines.

Secondary Tumor Arising in a Nevus Sebaceous

Introduction. Nevus sebaceous is a rare congenital hamartoma, composed of epidermis, sebaceous glands, sweat glands and hair follicles. It is possible to develop secondary tumors in the area of nevus sebaceous during the lifetime, most often after puberty. Secondary lesions are most often benign, while malignant lesions may occur but significantly less frequently.

Case report. We present the case of a 21-year-old patient who came for an examination due to the appearance of a nodule in the area of a yellowish lesion on the head. The yellowish lesion was present since birth, and the nodule appeared about a year before. The dermoscopic examination of the lesion was nonspecific. The final diagnosis of eccrine poroma as a secondary lesion in nevus sebaceous was made by pathohisto-logical analysis.

Conclusion. Every secondary tumor in nevus sebaceous deserves full attention, with either close follow up, or excision with pathohistological analysis.

Eccrine Poroma Arising within Nevus Sebaceous

Secondary neoplasms in nevus sebaceous can develop during adolescence and adulthood. Trichoblastoma and syringocystadenoma papilliferum are the most common benign neoplasms, but poroma is rarely reported. A 28-year-old female presented with an asymptomatic mass on the scalp. She has had a hairless lesion on the scalp since birth. A soft mass developed on that lesion four years prior. Physical examination revealed a localized 1 cm×2.5 cm-sized brownish, verrucous-surfaced plaque with a 1 cm×1 cm-sized pedunculated erythematous tumor on the scalp. We performed skin biopsy on both the plaque and tumor lesions. The histopathological findings demonstrated the plaque lesion consistent with nevus sebaceous and the tumor lesion consistent with eccrine poroma. Surgical mass excision was performed. The patient was eventually diagnosed with eccrine poroma arising within nevus sebaceous. To the best of our knowledge, there are only six reported cases on poroma arising within nevus sebaceous. Although rarely documented in the literature, it should be considered as a secondary neoplasm within nevus sebaceous.

Characteristic Clinical and Dermoscopic Features of Nonvolar Poroma

BACKGROUND

A poroma typically presents as a solitary, pink-to-red papule or nodule in acral volar areas. However, in nonvolar areas, this typical clinical feature (TCF) can be difficult to identify.

OBJECTIVE

We aimed to compare clinical and dermoscopic characteristics between nonvolar poroma (NVP) and volar (ie, typical) poroma (VP).

METHODS

We assessed the clinical and dermoscopic characteristics of 40 patients with poromas who were divided into the NVP and VP groups.

RESULTS

Of the 40 patients, 20 (50.0%) were allocated to the NVP group and 20 (50.0%) to the VP group. Pigmented variants were more common in the NVP group than in the VP group (60.0% vs 5.0%). The TCF of poroma was observed less frequently in the NVP than the VP group (45.0% vs 85.0%). Approximately one-third (30.0%) of patients with NVP received an initial clinical diagnosis of skin cancer. Dermoscopic patterns associated with melanoma or basal cell carcinoma were more common in the NVP group than in the VP group (65% vs 30%).

CONCLUSIONS

Skin cancer-associated clinicodermoscopic features were more frequently observed in patients with NVP, who simultaneously lost dermoscopic patterns associated to poromas and acquired those associated with skin cancer, than those with VP.

Eyelid Eccrine Poroma: A Case Report and Review of Literature

Poroma is a rare benign tumor of the epidermal sweat duct unit with predilection for the head and neck. Only six cases with eyelid location have been described in the literature (PubMed). A 34-year-old male presented with a single tumor on the left upper eyelid. It was skin-colored, nodular, solid, tender with some telangiectatic vessels, and showed no ulcerated lesion. Clinical diagnosis was basal cell carcinoma. This type of lesion can mimic a malignancy. Complete excisional biopsy revealed features consistent with eccrine poroma. After three year of follow up, no recurrence was observed. The authors reviewed all the cases reported in the literature and made a summary comparing them.

A Growing Mass under the Nail: Subungual Eccrine Poroma

Eccrine poroma is a benign adnexal tumour, which originates from the acrosyringium of eccrine sweat glands. Eccrine poroma is an uncommon neoplasm, the typical clinical presentation of which is a solitary soft sessile reddish papule protruding from a cup-shaped shallow depression. Many challenges remain in the diagnosis of eccrine poroma because it does not always present with classical features and may mimic any other cutaneous benign and malignant lesions. Eccrine poromas may occur on any skin surface with sweat glands; on the other hand, the most common sites of involvement include the palms and soles, which are rich in eccrine sweat glands. Here, we present a case of subungual eccrine poroma, which is an extremely rare presentation of poromas. We also highlight dermoscopic features of eccrine poroma and review the available literature on the subject.

A Painful Step - Pendulating Plantar Eccrine Poroma

BACKGROUND

Eccrine poroma is a benign tumour of eccrine duct epithelium. The usual clinical presentation is nodular.

CASE REPORT

We present a 78-year-old man with a painful pendulating flesh-coloured malodorous plantar tumour. Differential diagnoses included telangiectatic granuloma, acrochordon, basal cell or squamous cell carcinoma, cylindroma, amelanotic melanoma, and verruca. Microbiological investigations identified numerous bacteria including Corynebacterium striatum, Streptococcus dysgalactiae, Staphylococcus aureus, Citrobacter koseri. We performed surgery since the tumour hampered his mobility. Histopathology revealed a well-circumscribed tumour composed of cuboidal cells with eosinophilic cytoplasm. Healing was unremarkable.

CONCLUSIONS

Pendulating plantar eccrine poroma is a rare clinical presentation of this benign adnexal tumour. Often asymptomatic, in some cases the tumour may become painful. Because of the bacterial colonisation, it could lead to deep soft tissue infections. Malignant transformation is possible. Surgical removal is the treatment of choice.

Results of Surgical Treatment of Patients with Malignant Eccrine Poroma

Objectives:

Malignant eccrine poroma is a rare cutaneous malignancy. This study was a review of a series of patients with malignant eccrine poroma who underwent surgical treatment conducted in order to evaluate the management techniques and outcomes of treatment modalities.

Methods:

All cases of surgically excised malignant eccrine poroma performed in a single clinic between 2012 and 2018 were included in the study. The details of patient age, gender, anatomical location of the tumor, histopathological features, and treatment modalities were analyzed.

Results:

The average tumor size was 2.53 cm (range: 0.3-7 cm). The average tumor thickness was 3.06 mm (range: 2.5-4 mm). The mean clean tumor margin after the first excision was 1.28 mm and the mean tumor margin after the second excision was 8.83 mm. No recurrence or distant metastasis was detected in any of the patients during the follow-up period.

Conclusion:

Unlike frequent skin cancers, rare skin cancers, like malignant eccrine poroma, don’t have definite treatment algorithms constituted from randomized trials. The findings of patient series are very useful to guide physicians in these cases.

Initial Misidentification of Thumb Poroma by Shave Biopsy

Poromas are benign adnexal neoplasms originating from the intraepidermal portion of sweat gland ducts. With the possibility of malignant transformation, accurate clinical diagnosis and treatment are crucial. Numerous reports of hand poroma lesions have been reported. We present an unusual case of a distal thumb poroma originally identified as a squamous cell lesion in a shave biopsy and eventually accurately identified after excisional biopsy. This report highlights the limitations of shave biopsy associated with soft tissue hand lesions and the need to consider poroma when evaluating a soft tissue lesion of the hand.

Recurrent Metastatic Eccrine Porocarcinoma: A Case Report and Review of the Literature

Patient: Male, 67

Final Diagnosis: Recurrent metastatic eccrine porocarcinoma

Symptoms: Skin lesion

Medication: —

Clinical Procedure: —

Specialty: Dermatology