Eccrine porocarcinoma (malignant eccrine poroma): a clinicopathologic study of 69 cases

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.

The transition between a poroma and a porocarcinoma evidenced by the dermoscopy

Eccrine porocarcinoma (EPC) is a rare malignant skin tumor. The dermoscopy of invasive EPC reveals focal presence of whitish-pink, structureless areas surrounded by pinkish-white halos. In an eccrine poroma (EP), such areas present diffuse distribution in the "frog- eggs" pattern. We reported an EPC in situ that presents a transitional dermoscopy pattern between EP and invasive EPC. We found a diffuse distribution; whitish-pink, structureless areas surrounded by pinkish-white halos; a central exulceration and a polymorphic vascular pattern.

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

Eccrine porocarcinoma on the cheek

Eccrine porocarcinoma is a rare malignant tumor arising from the intraepidermal ductal portion of the eccrine sweat gland. It develops either spontaneously or from a long standing benign eccrine poroma. This entity usually affects older people and is commonly located on the lower extremities, the trunk, and the head. We report a case of eccrine porocarcinoma on the left cheek in an 85-year-old male. In our case, the tumor was treated with wide excision and postoperative adjuvant radiation therapy. The patient recovered well without local recurrence and distant metastasis during the 14-month follow-up period. Wide excision and postoperative adjuvant radiation therapy can be considered as a safe and effective treatment option in treating patients with eccrine porocarcinoma.

Sentinel lymph node biopsy in porocarcinoma: A case reports

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Epidemiology of rare cutaneous tumor: EPC.

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Role of Surgery excision.

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Role of SNLB for staging and diagnosis in EPC.

Introduction

Eccrine porocarcinoma (EPC) is a slow-growing carcinoma arising from the eccrine sweat glands. Based on its clinical presentation it can be confused with malignant and benign skin lesions, both. Histological examination is essential to formulate a correct diagnosis. Surgical excision with clear margins is the standard therapeutic approach while the role of sentinel lymph node biopsy (SNLB) remains controversial.

Case presentation

The Authors report two cases of EPC of the lower limbs occurred in two women. Patients were treated by wide surgical excision of the lesion and SNLB. 6 months follow-up was disease free for both patients.

Conclusion

Although a rare cutaneous tumor, EPC has to be taken into account in the differential diagnosis of malignant skin lesions because of its possible loco-regional aggressiveness and related morbidity. Among the available treatment options, surgical excision is considered the standard approach whereas the role of SNLB is controversial although the Authors discuss a possible usefulness for staging and diagnosis.

Eccrine Porocarcinoma: New Insights and a Systematic Review of the Literature

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm with high potential for morbidity and mortality. Due to its rarity, there is a paucity of data profiling diagnosis, work-up, and management.

OBJECTIVE

To consolidate reported information on demographics, diagnostics, clinical behavior, treatment modalities, and patient outcomes in EPC to provide a reference tool to optimize diagnosis and management.

METHODS

A comprehensive PubMed search was performed from 1963 to November 2017 using PRISMA guidelines. This yielded 155 articles detailing 206 cases of porocarcinoma.

RESULTS

Eccrine porocarcinoma most often presents in elderly patients on the head and neck or lower limbs. Metastatic disease at presentation is not uncommon (22%). Primary tumor location is significantly correlated with presence of metastasis (p = .038). The most common treatment is excision followed by Mohs micrographic surgery (MMS), although the outcomes after MMS were superior to those after surgical excision.

CONCLUSION

This systematic review of individual patient data reveals that all patients should have a histological diagnosis with imaging considered for high-risk cases. Primary tumor location should also be considered in diagnostic and therapeutic decision-making. Although wide local excision (WLE) is currently the first-line treatment, MMS is becoming increasingly used, with evidence indicating improved outcomes as compared to those seen with WLE.

Targeted molecular profiling reveals genetic heterogeneity of poromas and porocarcinomas

The genetic landscape of rare benign tumours and their malignant counterparts is still largely unexplored. While recent work showed that mutant HRAS is present in subsets of poromas and porocarcinomas, a more comprehensive genetic view on these rare adnexal neoplasms is lacking. Using high-coverage next generation sequencing, we investigated the mutational profile of 50 cancer-related genes in 12 cases (six poromas and six porocarcinomas). Non-synonymous mutations were found in two-thirds of both poromas and porocarcinomas. Hotspot HRAS mutations were identified in two poromas (p.G13R and p.Q61R) and one porocarcinoma (p.G13C). While in poromas only few cases showed single mutated genes, porocarcinomas showed greater genetic heterogeneity with up to six mutated genes per case. Recurrent TP53 mutations were found in all porocarcinomas that harboured mutated genes. Non-recurrent mutations in porocarcinomas were found in several additional tumour suppressors (RB1, APC, CDKN2A, and PTEN), and genes implicated in PI3K-AKT and MAPK signalling pathways (ABL1, PDGFRA, PIK3CA, HRAS, and RET). UV-associated mutations were found in TP53, APC, CDKN2A, PTEN, and RET. In conclusion, our study confirms and extends the spectrum of genetic lesions in poromas and porocarcinomas. While poromas exhibited only few mutations, which did not involve TP53, the majority of porocarcinomas harboured UV-mediated mutations in TP53 with some of these cases showing considerable genetic heterogeneity that may be clinically exploitable.

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

INTRODUCTION

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

CASE PRESENTATION

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

CONCLUSION

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

A case of massive porocarcinoma

A 53-year-old Cambodian woman presented with nodular masses on the right arm suggestive of a sarcoma-type malignancy. The masses were excised and identified as multiple benign eccrine poromas. The patient re-presented after two years with large relapsed tumours and axillary lymph node involvement. A forequarter amputation was undertaken. Histology confirmed the diagnosis of a porocarcinoma, which was likely to be due to malignant transformation of the original poromas. The size and multiplicity of the tumours represents a highly unusual presentation of these rare eccrine neoplasms.

Concomitant poroma and porocarcinoma

Eccrine poromas and porocarcinomas are adnexal tumors derived from the sweat duct epithelium. However, eccrine poroma is benign in nature, whilst eccrine porocarcinoma is regarded as its malignant counterpart. We report the case of a man who presented simultaneously with an eccrine poroma and eccrine porocarcinoma. Both lesions had no clear distinctive features, enhancing the need of high-level clinical suspicion together with surgical excision and histopathology for prompt diagnosis confirmation.

Squamoid Eccrine Ductal Carcinoma: A Clinicopathologic Study of 30 Cases

Squamoid eccrine ductal carcinoma is a poorly documented skin adnexal carcinoma showing squamous and duct differentiation. It is regarded to be of low-grade malignant potential, but limited follow-up information is available. To study their clinical behavior and histologic features, 30 squamoid eccrine ductal carcinomas were identified from departmental and referral files. Hematoxylin and eosin-stained sections were reviewed, and immunohistochemistry for carcinoembryonic antigen and epithelial membrane antigen was examined to confirm duct differentiation. Clinical follow-up was obtained from patient records and referring pathologists. The tumors presented as nodules or plaques (median size, 1.0 cm; range, 0.5 to 2.5 cm) with a predilection for the head and neck (77%). The patients were elderly (median age, 79.5 y; range, 10 to 96 y) with a male predominance. Histologically, these poorly demarcated tumors were characterized by an infiltrative growth pattern within the dermis and additional invasion of subcutis in 70%. Median tumor thickness was 4.3 mm (range, 1.5 to 18 mm). Superficially, the tumors resembled well-differentiated squamous cell carcinoma. In the deeper reaches, they were organized in cords and strands showing duct differentiation in a desmoplastic stroma. Cytologic atypia was moderate to severe. Ulceration (47%), necrosis (23%), and perineural and lymphovascular infiltration (27% and 6%, respectively) were additional features. Follow-up data (median, 29 mo; range, 7 to 99), available for 24 patients (80%), revealed a local recurrence rate of 25%. Three patients had lymph node metastasis, and 1 patient died of metastatic disease. Our study outlines the histologic characteristics of squamoid eccrine carcinoma and emphasizes its clinical behavior with risk for local recurrence and potential for more aggressive behavior with metastasis and rare disease-related mortality.

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

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

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

BACKGROUND

porocarcinoma is a rare sort of skin cancer developing from sweat glands. Its clinical course and management are not well understood.

OBJECTIVES

the current meta-analysis is to address the presentation and management of porocarcinoma.

DATA SOURCES

Web of Science, PubMed, MEDLINE on OVID and Google scholar were searched for English-language studies published before December 1, 2016.

RESULTS

The review of literature revealed 453 cases. From which 222 (49%) cases were male and female were 231 (51%). The mean age was 67.57 years. The mean duration of presentation was 5.57 years ranging from 4 days to 60 years of age. The most common site of affection is the head and neck (39.9%) followed by lower extremity (33.9%). Mass and nodule are the most common modes of presentation. Metastasis occurred at presentation in 110 (31%) cases. The most common organ to which porocarcinoma metastizes is the nearby lymph node (57.7%).

CONCLUSIONS

Porocarcinoma is an aggressive skin cancer. Surgery is the main modality of treatment.

SYSTEMATIC REVIEW REGISTRATION NUMBER

reviewregistry233.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Eccrine Poroma of the Postauricular Area

Eccrine poroma is a common benign cutaneous tumor that originates in an intraepidermal eccrine duct. This tumor exhibits acral distribution (sole, palm), and is rarely encountered in the head and neck area. In fact eccrine poroma in the postauricular area has only been rarely reported. A 55-year-old female visited our hospital with a main complaint of a mass that first developed in the left postauricular area about a year previously. The mass was painless, soft, protruding, domed, and dark red in color, and had slowly enlarged (at presentation it measured 1×1 cm). Excisional biopsy was performed. Histological examination showed distinct features, and eccrine poroma was diagnosed. Follow-up at 6 months postoperatively showed no recurrence. The frequency of eccrine poroma is dependent on eccrine sweat glands density, and thus, usually occurs on the palms or soles. For eccrine poroma in the head and neck region, the differential diagnosis must rule out other masses, such as nevus, skin tag, pyogenic granuloma, cyst, basal cell carcinoma, and seborrheic keratosis. Importantly, 18% of poromas show malignant transformation, and can develop into porocarcinoma. For these reasons, an eccrine poroma in the facial area requires histological examination, complete excision, and follow-up.

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

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

Cytodiagnosis of Eccrine Porocarcinoma of the Scalp

Eccrine porocarcinoma is a rare, malignant adnexal tumor of the duct of eccrine sweat gland. Cytology of eccrine porocarcinoma has been described in very few previous literature. Here, we present a case of fine needle aspiration cytology (FNAC) of eccrine porocarcinoma of the scalp, which is subsequently confirmed by histology. Accurate diagnosis of eccrine porocarcinoma by FNAC is very difficult, but determining the malignant nature of the lesion is crucial for curative surgery. FNAC can be a convenient, safe, and effective approach to solve difficult diagnostic dilemma.

Porocarcinoma: A systematic review of literature with a single case report

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Porocarcinoma is a rare but aggressive type of skin malignancy.

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Reporting new cases is mandatory to outline the course of the disease.

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We systematically reviewed the literature with a new case report.

Introduction

Eccrine porocarcinoma is a very rare type of skin cancer. It is an aggressive dermatological malignancy. We presented a 62-year-old male with long history of a mass in left forearm complicated by distant metastasis and death. A rapid review of literature has been presented.

Conclusion

Eccrine porocarcinoma is a rare but aggressive type of skin disease. It may arise de novo or complicate a benign skin lesion. Wide local resection is recommended.

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

Background

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

Case presentation

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

Conclusions

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

Eccrine Porocarcinoma Presenting as a Hand Cyst

Eccrine porocarcinoma is a rare tumor that arises from the epithelium of the eccrine ducts, with a tendency for metastatic spread and a high rate of local recurrence after excision. It was first described in 1963 by Pinkus and Mehregan and can present clinically as a nodule, erosive plaque or a polypoid growth that may ulcerate. The variable clinical appearance of these lesions can make diagnosis challenging and could delay appropriate treatment. If metastasis occurs the prognosis is poor, with a reported mortality rate of up to 80%. We report an uncommon presentation of porocarcinoma as a cyst on the dorsum of the right hand in a 37-year-old man. Only 8% of porocarcinomas occur in the upper extremity and only 3% are on the hand. Furthermore, the tumor is more common in females and mean age at diagnosis is 67 years. Treatment is with wide local excision with free tumor borders confirmed by biopsy, which has been shown to be curative in 70% to 80% of patients.

Metastatic Eccrine Porocarcinoma: A Rare Case of Successful Treatment

The successful treatment of the rare malignancy eccrine porocarcinoma (EP) is extremely challenging, often not rewarding and when associated with metastatic disease, therapy results are disappointing. We present a unique case of treatment response of metastatic EP, with a significant disease-free interval. The patient has remained in clinical and radiological remission for 36 months since diagnosis of metastatic disease.

Malignant Eccrine Poroma of the Vulva: An Intriguing Case of a Rare Tumor at an Unusual Site

Malignant eccrine poroma is a rare malignancy of the eccrine sweat glands, occurring most frequently on the lower extremities. It affects both sexes equally usually in the 6(th) to 7(th) decade of life. Metastasis to regional lymph nodes may occur in 20% that may be fatal in 60% cases. Its aggressive nature, rarity of occurrence, and unusual presentations make it very important to be evaluated properly by the clinician. We hereby report a case of a 75-year-old female presenting with two exophytic tumors over her vulva with local extension. On histopathological examination, it was diagnosed as malignant eccrine poroma. On magnetic resonance imaging of the pelvic region, metastatic extension in regional lymph nodes was found. She was treated by radical vulvectomy with bilateral inguinal and femoral lymph node dissection followed by radiotherapy.

Cutaneous Collision Tumor Associated With Porocarcinomatous and Angiosarcomatous Components: A Potential Diagnostic Pitfall

Sarcomatoid eccrine porocarcinoma (SEP) is a very rare malignancy including epithelial and mesenchymal components exhibiting pleomorphic cells, nuclear hyperchromasia, and high mitotic activity in both elements. To date, only 6 cases of this uncommon neoplasm have been reported, corresponding to women over 70 years of age with ulcerated skin lesions. The authors describe the first sarcomatoid eccrine porocarcinoma in a 75-year-old male patient with a right hallux lesion, presenting a collision tumor with a mixed population of epithelial cells and a spindle cell angiosarcomatous mesenchymal component each expressing distinct and nonoverlapping morphologic and immunohistochemical features of epithelial and mesenchymal differentiation.

Porocarcinoma scalp with high risk features treated with surgery and adjuvant radiotherapy: A case report and review of literature

Eccrine porocarcinoma is a rare malignant sweat gland tumor arising from the intra dermal part of the gland and accounts for only 0.005% of all epithelial cutaneous tumors. Commonly involved site includes extremities and face. Scalp is a rare site for porocarcinoma with less than 20 reported cases so far. Wide local excision with clear margins remains the treatment of choice. Review of literature revealed a local recurrence rate of 37.5% and a nodal involvement risk of 20%. Porocarcinoma of the scalp is peculiar in that the primary tumor may be large at presentation, making surgery with adequate margins difficult. Adjuvant radiotherapy must be considered in a case to case basis due to the high local recurrence rates compared to other sites of porocarcinoma and should be given to all patients with close margins and extra capsular extension.

Eccrine Porocarcinoma of the Eyelid in a Non-Caucasian Patient

A 60-year-old lady of Chinese origin presented with a right medial canthal mass. The lesion had been present for many years but progressively increased in size a few months prior to the consultation. Clinical examination revealed a medial canthal mass measuring 1.8 cm in diameter. It was firm with an irregular crusting surface. It was not attached to underlying deep lamella, and there were overlying telangiectatic vessels with contact bleeding. Excisional biopsy of the lesion confirmed a diagnosis of eccrine porocarcinoma. Eccrine porocarcinoma rarely occurs in the eyelid, and this is the first reported case of its occurrence in non-Caucasian patient. Given the significant risk of recurrence and metastasis, long-term surveillance is warranted. Although being rare, ophthalmologists should be vigilant of this potentially life-threatening lesion in the management of eyelid tumors.

Eccrine Porocarcinoma presenting as an abdominal wall mass in a patient with ulcerative colitis-A rare case report

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Eccrine Porocarcinoma (EPC) is rare. It seldom occurs in the early 20s, or arises in the abdominal wall

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EPC is easily misdiagnosed due to lack of specific morphological features. Clinical picture usually consists of a painless nodule or papule

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Definitive diagnosis is achieved by histopathological examination

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Early definitive surgical excision with wide tumor free margins leads excellent results. Risk of local recurrence is about 20%

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High index of suspicion for EPC should be maintained in patients with cystic abdominal wall masses, especially in case of ulceration or discharge

Introduction

Eccrine porocarcinoma (EPC) is a rare malignancy of eccrine sweat glands. It is often seen during the sixth to eighth decades of life. We report the first case of eccrine porocarcinoma arising on the abdomen of a 21-year-old patient with ulcerative colitis.

Case presentation

A 21-Year-old female presented to emergency department with a one month history of an enlarging mass over left lower abdomen. Abdominal examination revealed a slightly erythematous, nodular and non-mobile firm mass in left lower quadrant. There was superficial ulceration with slight serous discharge. CT scan of the abdomen and pelvis with contrast revealed a superficial cystic lesion over the anterior abdominal wall, provisionally diagnosed as sebaceous cyst. Incision and drainage were performed and on follow-up, no signs of healing were observed and the patient subsequently underwent surgical excision. Histopathological examination revealed an eccrine porocarcinoma.

Discussion

EPC is a rare and aggressive tumor. It may occur de novo or as a result of malignant transformation of an eccrine poroma. A long period of clinical history is often encountered. It usually occurs on the lower extremities followed by the, trunk, head and neck, and upper extremities. The clinical picture usually consists of a painless nodule or papule. Treatment is wide local excision. No strong evidence exists for adjuvant therapy. The risk of local recurrence is about 20%.

Conclusion

High index of suspicion is required for diagnosis of EPC. Early diagnosis is achieved by histopathological examination and early definitive surgical excision leads to excellent results.

Histomorphological and Immunohistochemical Reappraisal of Cutaneous Adnexal Tumours: A Hospital Based Study

Background. Diagnosing adnexal tumours of the skin is a challenge due to their wide variety, infrequent occurrence in practice, and confusing morphological picture. Aims and Objectives. The present study aims to observe the spectrum of adnexal tumours at our institute and to evaluate them based on histomorphological, histochemical, and immunohistochemical methods either alone or in combination for proper identification and classification. Materials and Methods. A partly retrospective and partly prospective study was conducted on adnexal skin tumours over a period of 6 years. Relevant clinical profile was recorded. Histopathological examination was carried out and special stains were applied as and when required. Immunohistochemistry was performed where diagnosis with routine stains was not possible. Results. A total of 150 skin tumour biopsies were received. There were 87 keratotic tumours, 39 adnexal tumours, and 24 melanocytic tumours. Amongst the adnexal tumours, 51.3% eccrine, 30.8% follicular, and 17.9% sebaceous tumours were seen. In five cases, histological diagnosis was troublesome where immunohistochemistry helped in making final diagnosis. Limitations. The sample size is small. Conclusion. Histomorphology is confirmatory in majority of the adnexal tumours but few rare lesions that mimic internal malignancy require a panel of immunomarkers to rule out other possible differentials.

Primary Axillary Porocarcinoma: A Rare Cutaneous Tumour

Eccrine porocarcinoma, a rare cutaneous malignant tumour accounts for a fraction of sweat gland tumours. This tumour is found to originate from the intraepithelial parts of the sweat glands. It commonly involves the lower extremities in elderly patients and carries an aggressive behaviour. Cutaneous and visceral metastasis can occur and hence prompt treatment is mandatory. Surgical excision is the mainstay of treatment modality. We hereby present a case of eccrine porocarcinoma in a 50-year-old male in the right axillary region presenting as a verrucous lesion.

Eccrine poroma and porocarcinoma on the same unusual location: report on two cases

Eccrine poroma is a benign adnexal tumour of the uppermost portion of the intraepidermal eccrine sweat gland duct and acrosyringium. Eccrine porocarcinoma is the malignant phenotype arising from the intraepidermal portion of the eccrine sweat gland duct epithelium or from pre-existing eccrine poroma. Both commonly occur in the palms or sides of the feet; these areas have a high concentration of eccrine sweat glands. We describe two respective cases of benign and malignant eccrine poroma on the scrotum, which entailed good excisional results.

Porocarcinomas harbor recurrent HRAS-activating mutations and tumor suppressor inactivating mutations

Porocarcinomas are a rare eccrine carcinoma with significant metastatic potential. Oncogenic drivers of porocarcinomas have been underexplored, with PIK3CA-activating mutation reported in 1 case. We analyzed 5 porocarcinomas by next-generation sequencing using the DNA component of the Oncomine Comprehensive Assay, which provides data on copy number changes and mutational events in 126 cancer-relevant genes through multiplex polymerase chain reaction. We detected an average of 3.3 high-confidence nonsynonymous mutations per tumor (range, 1-6), including a spectrum of oncogenic activation and tumor suppressor inactivation events. Tumor suppressor mutations included TP53 (4/5, 80%), RB1 (3/5, 60%), ATM (2/5, 40%), ARID1A (1/5, 20%), and CDKN2A (1/5, 20%). In 4 (80%) of 5 tumors, at least 1 potential oncogenic driver was identified. Activating HRAS mutations were detected in 2 (40%) of 5, including G13D and Q61L hotspot mutations. Mutations of EGFR were identified in 2 (40%) of 5; these mutations have been previously reported in cancer but did not affect classic activation hotspot sites. EGFR and HRAS mutations were mutually exclusive. HRAS mutations were detected by targeted sequencing in a minority of benign eccrine poromas (2/17; 11.7%), suggesting that HRAS activation may rarely be an early event in sweat gland neoplasia. Together, our data suggest roles for HRAS and EGFR as drivers in a subset of poroma and porocarcinoma. TP53 and RB1 inactivation events are also likely to contribute to tumorigenesis. These findings suggest that porocarcinomas display diversity with respect to oncogenic drivers, which may have implications for targeted therapy in metastatic or unresectable cases.

Eccrine porocarcinoma with extensive cutaneous metastases

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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