Cutaneous Horn Presentation in Porokeratotic Eccrine Ostial and Dermal Duct Nevus. A Brief Review and Case Report.

ABSTRACT: Porokeratotic eccrine ostial and dermal duct nevus is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia. Different clinical presentations have been reported in the literature. Here, we report a case of a 6-year-old girl diagnosed with porokeratotic eccrine ostial and dermal duct nevus confirmed by histopathologic study. Atypical lesions are described as whitish, warty-looking neoformations located in the anterolateral region of the right hip (cutaneous horn).

Porocarcinoma of the Left Foot: A Case Review.

Eccrine porocarcinoma is a rare malignant tumor of the eccrine sweat gland. This malignancy occurs most commonly in the lower extremities. It tends to occur in patients aged 60 to 80 years, affecting men and women equally. We present the case of a 62-year-old man with a lesion on the left foot. The diagnosis of the initial biopsy was squamous cell carcinoma. Six months later, the lesion reoccurred, and a second biopsy confirmed it to be eccrine porocarcinoma.

Eccrine Ductal Carcinoma of the Eyelid.

The authors present the third example of an eccrine ductal carcinoma of the eyelid. A woman in her early 70s presented with a lesion of the central right lower eyelid margin in the vicinity where an actinic keratosis was diagnosed by biopsy 2.75 years previously. Her dermatologist and ophthalmologist monitored the area of actinic keratosis, and it was stable for 2.5 years until the area became ulcerated and thickened with the loss of eyelashes. A wedge resection disclosed a squamous cell carcinoma in situ and a separate eccrine ductal carcinoma. The eccrine ductal carcinoma had in situ tumor thickening, an eccrine duct component, and an invasive tumor infiltrating the tarsal plate and replacing the normal meibomian glands. The invasive eccrine ductal carcinoma only mildly thickened the tarsal plate and was most likely an incidental finding in a biopsy prompted by the squamous cell carcinoma in situ. The 5-year relative survival rate for malignant apocrine-eccrine tumors is approximately 97%, and our patient is alive and without evidence of local or distant tumor recurrence 5.5 years following the excision of her eyelid tumor.

Eccrine Angiomatous Hamartoma with Atypical Localization Treated by Mohs Micrographic Surgery.

ABSTRACT: Eccrine angiomatous hamartoma (EAH) is a rare hamartoma characterized by a benign proliferation of eccrine glands and vascular structures in the dermis. These tumors rarely regress spontaneously, so surgical excision of the involved tissue is required when pain or enlargement occurs. Here, the authors report the clinical case of a patient affected by an extremely painful EAH with the atypical localization at the last phalanx of the thumb of the right hand with involvement of nail matrix and nail bed. This report aims to emphasize the application of Mohs micrographic surgery for the treatment of painful EAH in a very difficult area at potential risk of amputation while preserving the maximum anatomical integrity and function of the damaged area. These results can pave the way for the use of Mohs micrographic surgery for very carefully selected benign neoplasms when their surgical removal is required.

Whole-Exome Sequencing of a Case of Squamoid Eccrine Ductal Carcinoma Reveal Similarities With Cutaneous Squamous Cell Carcinoma.

ABSTRACT: Squamoid eccrine ductal carcinoma (SEDC) is a poorly documented but likely underrecognized sweat gland malignancy with significant risk for local recurrence and potential for metastasis and rare disease-related mortality. Histopathologically, the tumor demonstrates a biphasic differentiation pattern: superficially, the tumor has squamous differentiation [indistinguishable from well-differentiated cutaneous squamous cell carcinoma (cSCC)], while the deeper aspect has a more infiltrative pattern with prominent ductal differentiation. Diagnosis of SEDC relies upon histopathologic examination alone. Its pathogenesis is poorly understood, and its genomic features have yet to be described. In this article, we characterize the genomic features in a case of SEDC through whole-exome sequencing, then compare its features with cSCC and other eccrine ductal carcinomas. Whole-exome sequencing revealed 30 mutations/Mb with 21 pathogenic or likely pathogenic mutations in total, identified across 14 different genes. The genomic abnormalities identified in this case of SEDC overlap considerably with those found in cSCC but not those of other sweat gland malignancies. The clinical and histopathologic features of SEDC previously reported and the genetic features determined from this case suggest that this tumor may arise initially as a well-differentiated cSCC that subsequently undergoes divergent differentiation focally to resemble a sweat gland malignancy. Genetic analyses of additional cases are warranted to clarify this consideration.

Reactive Eccrine Syringofibroadenoma (ESFA) in Association With a Merkel Cell Carcinoma Excision Scar.

ABSTRACT: Eccrine syringofibroadenoma (ESFA) is a rare benign skin adnexal lesion of the acrosyringium of eccrine sweat ducts. Reactive ESFA, a subtype of ESFA, is usually associated with non-neoplastic cutaneous dermatoses or neoplastic skin tumors. Clinically, the lesions can be solitary or multiple, pink, or skin-colored coalescing papules or nodules of variable sizes. Histopathologically, this tumor is composed of numerous anastomosing cords of monomorphic cuboidal epithelial cells with eccrine duct formation. The association of reactive ESFA with benign conditions, such as psoriasis, diabetic polyneuropathy, scars, and leprosy, has been reported. However, the association of reactive ESFA with malignant tumors is extremely rare, with very few cases reported in the literature. We present a case of a 72-year-old woman who developed reactive ESFA associated with Merkel cell carcinoma excision scar. The ESFA tumors developed in the area of the surgical graft 10 months after the Merkel cell carcinoma had been excised. New ESFA tumors have continued to appear in the scar on a yearly basis while, so far, has been no recurrence of the original tumor. However, the presence of new tumor growths in the area suggested the possibility of recurrence of the Merkel cell carcinoma. That possibility was enhanced by the fact that PET scans revealed hypermetabolic activity in the ESFA papules.

Reactive Eccrine Syringofibroadenomatosis Associated With Venous Leg Ulcers: A Case Report and Literature Review.

Eccrine syringofibroadenoma (ESFA) is a rare adnexal tumor deriving from the acrosyringeal portion of the eccrine duct. Five subtypes of ESFA were described including a reactive form. Reactive ESFAs are associated with inflammatory and neoplastic dermatoses. In this article, we report the case of a 90-year-old woman presenting with 3 leg ulcers evolving for 2 years surrounded by large verrucous and eczematous lesions. Multiple skin biopsies showed anastomosing epithelial cords connected to the epidermis consistent with ESFA. We identified 8 cases of ESFA associated with chronic leg ulcers in the literature and reviewed their main clinical and histological features.

A possible role for second-hit postzygotic GJB2 mutation in porokeratotic eccrine ostial and dermal duct nevus.

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare type of epidermal nevus involving the eccrine acrosyringia. It typically presents as asymptomatic linear keratotic papules and plaques along the lines of Blaschko and predominantly affects the extremities. This disease has recently been linked to somatic mutations within the GJB2 locus. Only four GJB2 mutations have been previously documented for PEODDN, and the underlying genetic basis remains inconclusive. Herein, we report an 18-year-old female with a hyperkeratotic plaque on the dorsa of the proximal interphalangeal joint of her right ring finger, as well as multiple small hyperkeratotic papules linearly distributed on the lateral sides of her fingers occurring since birth. Histopathological results revealed prominent parakeratotic cornoid lamella-like tiers at the opening of the eccrine secretory ducts. Whole-exome sequencing of the affected skin tissue revealed a heterozygous germline mutation and a postzygotic somatic mutation in GJB2. In summary, this study presents a case of PEODDN with compound heterozygous mutations in GJB2, which broadens the genetic spectrum of this disease entity and implies a possible role for second-hit mutations in the pathogenesis of PEODDN.

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

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

Squamoid Eccrine Ductal Carcinoma of the Eyelid: Clinicopathologic Correlation of a Case.

Squamoid eccrine ductal carcinoma (SEDC) is a rare cutaneous neoplasm that often manifests as a plaque or nodule in sun-exposed areas of older patients. Herein, the authors report the first case of SEDC in the eyelid. A 76-year-old man presented with a 2.5 × 1.5 mm area of left upper eyelid erythema, thickening, ulceration, and scaling with madarosis superotemporally just above the lash line. Full-thickness wedge biopsy demonstrated irregular epithelial tubules with nuclear atypia and focal squamous differentiation, consistent with SEDC. The patient underwent Mohs resection and has had no recurrence approximately 27 months after surgical removal. The authors present this case to raise awareness of SEDC to ophthalmologists as all previous cases have been described in the nonophthalmic literature. A full-thickness biopsy is recommended to avoid misdiagnosing SEDC as squamous cell carcinoma (SCC), a less aggressive tumor. With greater awareness, there may be increased recognition of this likely underreported, more malignant entity.

Poorly Differentiated Metastatic Carcinoma of Possible Eccrine Sweat Gland Origin.

Sweat gland carcinomas are a rare group of cancer, representing less than .01% of all diagnosed skin malignancies. We report the case of a 32-year-old male who presented with a fungating lesion on the posterolateral side of his left knee. Immunohistochemical results were positive for cytokeratin 5/6 and cytokeratin 7, consistent with possible eccrine gland origin. Our patient underwent wide local excision of the mass with lymph node dissection. Pathology confirmed the diagnosis of poorly differentiated carcinoma of possible adnexal, eccrine gland origin. He completed taxol/cisplatin-based chemotherapy and radiation. Surveillance imaging showed bilateral lung nodules, a right pleural effusion, and peritoneal carcinomatosis, which were diagnostic of metastatic carcinoma. He started carboplatin and epirubicin chemotherapy and has been doing well. Because standard of care treatment options for metastatic eccrine carcinoma have not been developed, it is imperative to report these cases to better understand these complex tumors and their treatment.

Anhidrosis accompanied by cholinergic urticaria-like rash and dermal pain in a patient with Sjögren's syndrome.

Cholinergic urticaria (CholU)-like rash and dermal pain on sweating occur in patients with acquired idiopathic generalized anhidrosis (AIGA). However, it is unclear whether these are symptoms specific to AIGA among the various types of acquired generalized anhidrosis/hypohidrosis (AGAH). Moreover, the pathogenesis underlying CholU-like rash and dermal pain observed with anhidrosis remains to be clarified. A 20-year-old Japanese man with Sjögren's syndrome (SS) presented with anhidrosis. Transient stinging pain on the skin and pinpoint wheals were observed when his body temperature increased. Thermoregulatory sweat testing revealed anhidrotic areas covering 69% of the body surface area with a symmetrical distribution. A high concentration of histamine was detected (506 ng/mL) in the sweat. A skin biopsy specimen from the anhidrotic area showed the inflamed secretory portion of eccrine glands. This suggested inflammation-mediated damage to sweat glands, consistent with AGAH related to SS. Furthermore, immunohistochemical analysis revealed an ectopic distribution of dermcidin, a sweat-specific peptide, in the dermal tissue surrounding the secretory portion of eccrine glands. The expression of claudin-3, a tight junction (TJ) component of sweat glands, decreased or distributed in a mottled manner in the secretory portion. No decreased expression of muscarinic cholinergic receptor M3 was detected. These results suggested that sweat had leaked into the dermis in association with impaired TJ in the secretory portion, along with the damage to inflamed sweat glands related to SS. Collectively, CholU-like rash and dermal pain on sweating were observed in an AGAH patient with SS. The sweat leakage into the dermis may contribute to the development of the rash and pain.

A clinicopathological description of COVID-19-induced chilblains (COVID-toes) correlated with a published literature review.

BACKGROUND: The abundance of publications of COVID-19-induced chilblains has resulted in a confusing situation. METHODS: This is a prospective single-institution study from 15 March to 13 May 2020. Thirty-two patients received PCR nasopharyngeal swabs. Of these, 28 patients had a thoracic CT-scan, 31 patients had blood and urine examinations, 24 patients had skin biopsies including immunohistochemical and direct immunofluorescence studies, and four patients had electron microscopy. RESULTS: COVID-19-induced chilblains are clinically and histopathologically identical to chilblains from other causes. Although intravascular thrombi are sometimes observed, no patient had a systemic coagulopathy or severe clinical course. The exhaustive clinical, radiological, and laboratory work-up in this study ruled-out other primary and secondary causes. Electron microscopy revealed rare, probable viral particles whose core and spikes measured from 120 to 133 nm within endothelium and eccrine glands in two cases. CONCLUSION: This study provides further clinicopathologic evidence of COVID-19-related chilblains. Negative PCR and antibody tests do not rule-out infection. Chilblains represent a good prognosis, occurring later in the disease course. No systemic coagulopathy was identified in any patient. Patients presenting with acral lesions should be isolated, and chilblains should be distinguished from thrombotic lesions (livedo racemosa, retiform purpura, or ischemic acral necrosis).

Digital Papillary Adenocarcinoma in the Dorsal Proximal Ring Finger.

Digital papillary adenocarcinoma (DPA) is a rare and aggressive tumor arising from the eccrine sweat glands. It is found on the hands and feet and most commonly occurs on the volar and distal finger tips. In this report, we describe a DPA in a 45-year-old woman who presented with a slowly enlarging mass on the dorsal aspect of her proximal ring finger. This report shows that DPA may clinically present as a relatively benign-appearing mass and in an atypical location. Surgical excision, followed by histologic and immunohistochemical evaluations of even benign-appearing digital masses, is important because this is the only way a DPA can be diagnosed.

Cutaneous eccrine inflammation and necrosis: review of inflammatory disorders affecting the eccrine apparatus including new associations.

Despite being frequently overlooked during the examination of histopathological sections, eccrine sweat glands can offer clues for diagnosing various skin conditions. They provide important functions and can lead to several diseases when inflamed or injured. This review article provides information regarding eccrine physiology as well as well-established and novel entities that occur in association with eccrine gland pathology.

Leukemia cutis and eccrine squamous syringometaplasia.

Eccrine squamous syringometaplasia (ESS) is a histological term describing a mature squamous metaplasia of the eccrine ducts. Eccrine squamous syringometaplasia is not an infrequent histological finding and may be associated with chemotherapy or with a variety of non-specific conditions including infections, neoplastic conditions, and inflammatory skin diseases. We report a 75-year-old man who developed ESS within lesions of leukemia cutis (LC). The patient had an inaugural diagnosis of acute myeloid leukemia (AML) and he was not on chemotherapy when the biopsy was performed.