Poroid Hidradenoma Research Articles

Poroid Hidradenoma: A Rare Eccrine Tumor in an Unusual Location

Poroid hidradenoma (PH) is a rare benign neoplasm of eccrine origin, typically located within the dermis. It most commonly affects individuals in the sixth and seventh decades of life, though it can present at any age. The head, neck, and trunk are typical locations. This case report details a 26-year-old male with a large PH on the right hip, an atypical location. The lesion began as a small, painful nodule and progressively grew over 18 months. Initial treatment, suspected to be for an abscess, was unsuccessful. A dermatological evaluation revealed a 7 x 8 cm exophytic, ulcerated mass, and biopsy confirmed the diagnosis of PH. Histopathological analysis showed solid and cystic components, with poroid cells identified. Immunohistochemistry was positive for markers such as CEA, CK-7, and p63, which are consistent with this tumor type. Following the confirmed diagnosis, complete surgical excision was performed, and the patient remains asymptomatic with no signs of recurrence. Poroid hidradenoma is characterized by both poroid and cuticular cells, and although it is generally benign, malignant transformation has been reported in less than 1% of cases. Therefore, complete excision is recommended to reduce the risk of recurrence and malignancy. This case highlights the importance of early diagnosis and appropriate management of PH, including long-term follow-up to ensure the absence of recurrence.

Poroid Hidradenoma Presenting as a Malignant Neoplasm

Poroid hidradenoma is a rare adnexal neoplasm that presents with slow-growing solitary dermal or subcutaneous nodules with pink, red, or blue coloration. Malignant transformation has been reported in about 1%; however, clinical and histologic characteristics may present similarly with malignant neoplasms. A 60-year-old, Filipino, female presented with a 1-month history of a solitary, brownish-black papule on the right cheek progressing to a translucent friable nodule with associated bleeding after minimal trauma. The patient was initially assessed as a case of basal cell carcinoma due to its rapid growth. Hence, the patient was referred to a dermatologic surgeon for biopsy. Poroid hidradenoma was confirmed histologically and was managed with local excision. Poroid hidradenoma presenting with rapid growth is a very rare occurrence.

Case Report: Thigh hidradenoma masquerading as lipoma

Background: Hidradenomas are benign adnexal neoplasms which were recently been subdivided into two groups: eccrine differentiation (poroid hidradenomas) or apocrine differentiation (clear cell hidradenomas) with the latter being rarer. These types of tumors have been associated with recurrence and malignant transformation, however; recurrence and malignancy are considered very rare. We present a case report of a 35-year-old male who presented with two lumps, clinically representing simple lipomas but one of them turned to be a hidradenoma.

Poroid Neoplasms: A Clinicopathological Study of 13 Cases.

Poroid neoplasms (PN) are a heterogeneous group of tumors deriving from sweat glands and folliculo-sebaceous units. Their histological classification and clinical features are challenging. Our aim was to report clinicopathological features of poroid neoplasms. It is a retrospective study including all cases of poroid neoplasms registered at our Pathology laboratory of Niamey National Hospital (February 2020-February 2024). We registered 13 cases of benign poroid neoplasms: 10 classic poromas (CP) (76.9%), 2 poroid hidradenomas (PH) (15.4%) and 1 dermal duct tumor (DDT) (7.7%). Nine cases (69.2%) had preoperative clinical diagnosis of malignancy. The mean age was 41.1 years (range of 12-70 years) with a slight female predominance. Only 4/13 cases (30.8%) had classical palmoplantar locations. The tumors mean size was 3.7 cm (range of 0.4-8 cm). Clear cells were present in 7 cases (53.8%), apocrine ductal differentiation (mixed or pure) in 6 cases (46.2%), keratin horns in 2 cases (15.4%), squamous eddies in 6 cases (46.2%), melanin pigments in 1 case (7.7%) and sebaceous differentiation in 2 cases (15.4%). Unlike what is classically reported, our study shows that apocrine ductal differentiation, younger age and non-palmoplantar locations are common in poroid neoplasms.

NUT Expression Is of Diagnostic Utility in the Distinction of Digital Papillary Carcinoma From Poroid Hidradenoma.

The distinction between digital papillary adenocarcinoma (DPAC) and benign cutaneous adnexal tumors is clinically important and can be challenging. Poroid hidradenoma frequently occurs at acral sites and can show a number of histological features, which overlap with digital papillary adenocarcinoma. Recent work has shown that YAP1-NUTM1 fusions are frequent in poroid hidradenoma and are associated with nuclear protein in testis (NUT) expression by immunohistochemistry. We evaluated the expression of NUT-1 by immunohistochemistry in 4 cases of DPAC and 4 cases of poroid hidradenoma. Three of 4 cases of poroid hidradenoma showed strong NUT-1 expression, with no staining in any of the cases of DPAC. These results suggest that NUT-1 immunohistochemistry may be a useful additional tool in evaluating this differential diagnosis.

Poroid Hidradenoma of the Scalp with Adipocytic Metaplasia - A Rare Entity

Poroid Hidradenoma of the Scalp with Adipocytic Metaplasia - A Rare Entity

Poroid hidradenomas – a case series

Introduction: Poroid hidradenomas (PH) are rare benign skin adnexal tumours with eccrine differentiation. PH have features of both poroma and hidradenoma, and are wholly intradermal. Few PH have been reported in the literature, and here we present two cases of PH localised to the left knee. The common histological examination finding was a circumscribed cyst lined by basaloid cells resembling poroma, with occasional ductal structures. Case reports: Patient 1 is a 27-year-old male who underwent resection of a cyst on the left knee. A fragment of tan tissue was received. Microscopic examination showed a cyst surrounded by fibrous stroma, with no solid component. There was evidence of rupture with granulomatous inflammation and cholesterol clefts. The cyst lining showed basaloid to squamoid cells resembling poroma, with occasional ductal structures. The case was signed out as a poroid hidradenoma. Patient 2 is a 63-year-old male who underwent resection of a cyst on the left knee. A 5 mm cyst was evident macroscopically. Microscopic examination demonstrated a cystic lesion lined by choroid and cuticular type cells. There were duct like structures within the cyst wall, and the cyst contained eosinophilic material. The case was signed out as a cystic poroid hidradenoma.

Clinicopathological and genomic copy number variation analysis in nodular hidradenoma and hidradenocarcinoma with focus on prognostically important features

Nodular hidradenoma is a cutaneous adnexal tumor of sweat gland origin, characterized by its diverse but overlapping histomorphologic features with other skin tumors. In addition, distinction of benign hidradenoma and its malignant counterpart hidradenocarcinoma can be challenging, especially in prognostic prediction. We retrospectively reviewed pathological features of 29 cases, including benign nodular hidradenoma (n=17) and hidradenocarcinoma (n=12), with clinical follow-up ranging from 18 to 216 months. Genomic copy number variation (CNV) was studied in selected cases (n=18) by single nucleotide polymorphismmicroarray. None of the benign hidradenomas (0/17) or low-grade hidradenocarcinomas (0/6) had recurrence or metastasis after complete excision, whereas all 6 high-grade hidradenocarcinomas (6/6) showed locally destructive disease, recurrence, or local metastases. In benign hidradenomas, CNV abnormality was absent in all clear cell hidradenomas (0/5) but was detected in a considerable portion of poroid hidradenoma (3/5), with number of abnormalities ranging 2, 4, and 9. In malignant cases, regardless of morphological classification, both low-grade hidradenocarcinomas demonstrated limited CNV abnormalities in 2 areas (2/2), whereas all high-grade hidradenocarcinomas contained 8 or more CNV abnormalities (6/6). No disease-associated death was recorded in the cohort except one case was lost to follow-up after the development of metastatic disease. Overall, the findings support that genomic CNV abnormalities may serve as a sensitivebut less specific tool in detecting malignancy in these tumors, and potentially have a role in predicting clinical behavior particularly in the tumors of nonporoid morphology.

Poroid Hidradenoma over Dorsum of the Hand

Poroid hidradenoma is a rare, benign cutaneous neoplasm which presents as a solitary swelling. It has eccrine differentiation with features of both hidradenoma and poroma. We hereby present a case of a 50-year-old female patient with a slowly growing asymptomatic lesion over the dorsum of the left hand for 1½ years. Histopathology was consistent with poroid hidradenoma. The hidradenoma component consists of solid and cystic areas and poroma by poroid and cuticular cells. There was no recurrence of the lesion after 1 year of follow-up. Very few cases of poroid hidradenoma have been reported in the literature.

Trichilemmal cysts with proteinaceous material: A potential diagnostic pitfall.

Cysts of the skin are observed frequently and their diagnoses are generally straightforward. However, atypical cystic lesions for which differentiation is indistinct have been noted. We examined five cases of trichilemmal cyst with proteinaceous material (TCPM), which required differentiation from sweat duct/gland tumors. We investigated the histopathological findings of TCPMs and evaluated the immunohistochemical expression of cytokeratin (CK) 10, CK13, CK17, CK19, CD8, and CD117. Immunohistochemical analysis was performed on the 5 TCPMs, 10 trichilemmal cysts (TCs), 5 clear-cell hidradenomas, 5 poroid hidradenomas, and cutaneous normal adnexa. Apoptotic cells were present in the cyst wall with a small amount of keratin or calcification in the cavity of TCPMs. The TCPMs and TCs were negative for CK19 and CD117, on the other hand clear-cell hidradenoma and poroid hidradenoma were positive for CK19 and CD117. The restricted positivity for CK10 was detected in the suprabasal layers of the cyst walls of TCPMs and TCs. The immunostaining patterns of TCPMs and TCs were similar to those of normal follicular isthmus. The histopathological findings with characteristics of TCs and a panel of immunohistochemical antibodies including CD117, CK19, and CK10 contributed to a correct diagnosis of TCPM.

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.

Poroid Hidradenoma: Dermoscopic and In Vivo Reflectance Confocal Microscopic Description

Poroid hidradenoma (PH) is a rare, benign adnexal neoplasm usually presenting as a solitary, well circumscribed, asymptomatic papule or nodule that appears reddish and is occasionally tender. Since 1990, only a few cases of PH have been reported. We present a case of PH on the medial surface of the thigh and describe, for the first time, the dermoscopic and reflectance confocal microscopic (RCM) features in correlation with histology. A 67-year-old woman with unremarkable family or past medical history presented with a nodular lesion on the medial surface of the right thigh. The lesion had appeared 4 months earlier and rapidly enlarged. Physical examination revealed a 7 × 5 mm, non-tender, reddish nodule with clinically distinct margins. Dermoscopy showed central blue-grey pigmented areas, a polymorphous vascular pattern with arborizing, glomerular and hairpin vessels surrounded by white halos. RCM revealed an ovoid, well-outlined tumor, with a central area containing cells with distinctive morphologies, two types of tumor cells, tubular hypo-reflective structures, and rectilinear vessels in the stroma. These findings correlated with histological features, which established the diagnosis of PH. Even though the diagnosis of PH remains histopathological, non-invasive tools, such as RCM, can help rule out several malignancies, therefore reducing surgical-associated comorbidity.

A Large Mass over the Foot due to the Coexistence of an Eccrine Poroma and a Poroid Hidradenoma: A Case Report.

Eccrine poroma and poroid hidradenoma are uncommon benign poroid neoplasms derived from eccrine sweat glands. There are four types of poroid neoplasms according to the position within the skin layer: hidroacanthoma simplex, eccrine poroma, dermal duct tumor, and poroid hidradenoma. Poroid neoplasms usually arise as slow-growing solitary lesions and can present different clinical presentations, such as a foot mass, an ulceration lesion, a solid cyst, a bleeding lesion or suspected melanoma. Extremities are the most common sites, especially hands and feet. However, the coexistence of these two tumors in a single lesion is extremely rare. Surgical excision represents the main treatment and can be curative, preventing malignant changes and recurrence. We describe a rare solitary tumor over the foot with clinical and histopathological features of an association of an eccrine poroma and a poroid hidradenoma that was surgically treated with no recurrence at the midterm follow-up. Level of Evidence IV, Case Report.

NUT Is a Specific Immunohistochemical Marker for the Diagnosis of YAP1-NUTM1-rearranged Cutaneous Poroid Neoplasms.

YAP1-NUTM1 fusion transcripts have been recently reported in poroma and porocarcinoma. NUTM1 translocation can be screened by nuclear protein in testis (NUT) immunohistochemistry in various malignancies, but its diagnostic performance has not been thoroughly validated on a large cohort of cutaneous epithelial neoplasms. We have evaluated NUT immunohistochemical expression in a large cohort encompassing 835 cases of various cutaneous epidermal or adnexal epithelial neoplasms. NUT expression was specific to eccrine poromas and porocarcinoma, with 32% of cases showing NUT expression. All other cutaneous tumors tested lacked NUT expression, including mimickers such as seborrheic keratosis, Bowen disease, basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, nodular hidradenoma, and all other adnexal tumors tested. Remarkably, NUT expression was more frequent in a distinct morphologic subgroup. Indeed, 93% of poroid hidradenoma (dermal/subcutaneous nodular poroma, 13/14) and 80% of poroid hidradenocarcinoma cases (malignant poroid hidradenoma, 4/5) showed NUT expression, in contrast to 17% and 11% of classic poroma (4/23) and porocarcinoma cases (4/35), respectively. RNA sequencing of 12 NUT-positive neoplasms further confirmed the presence of a YAP1-NUTM1 fusion transcript in all cases, and also an EMC7-NUTM1 gene fusion in a single case. In the setting of a cutaneous adnexal neoplasm, nuclear expression of NUT accurately and specifically diagnosed a specific subgroup of benign and malignant poroid tumors, all associated with a NUTM1 fusion, which frequently harbored a poroid hidradenoma morphology.

Poroid hidradenoma: a benign lesion masking as a malignant breast tumor.

Poroid hidradenoma: a benign lesion masking as a malignant breast tumor.

Clinicopathologic Characterization of Hidradenoma on Acral Sites: A Diagnostic Pitfall With Digital Papillary Adenocarcinoma.

Hidradenomas are benign sweat gland tumors that typically present as small nodules in adulthood. Their anatomic distribution is wide and rarely includes acral sites. In this setting, reliable separation from digital papillary adenocarcinoma is important, but notoriously difficult. Hematoxylin and eosin-stained sections of 25 hidradenomas on acral skin were retrieved. The clinical presenting features and morphologic findings were recorded, and follow-up was obtained. Immunohistochemistry was performed for AE1/3, CK5/6, EMA, CEA, SMA, S100, p40, and p63. The tumors presented as solitary nodules on the hands (n=17) and feet (n=8) of adults (age range: 20 to 81 y; median: 50 y), with an equal sex distribution. Histologically, the well-circumscribed tumors were lobular, with a solid and cystic growth within dermis. Duct and squamous differentiation and vascularized hyaline stroma were frequent. The majority (n=18) were poroid hidradenomas. Scattered cytologic atypia and mitotic activity (median: 2/10 HPF) were common, and a pseudoinfiltrative growth of strands in a hyaline to sclerotic matrix was noted in 5 tumors. No papillary structures, atypical mitoses, or tumor necrosis were present. Immunohistochemically, all tumors expressed AE1/3, CK5/6, p40, and p63 strongly and diffusely. Luminal differentiation was highlighted by epithelial membrane antigen and carcinoembryonic antigen staining. S100 and SMA staining was absent. Follow-up (1 to 288 mo; median: 61 mo), available for 20 patients, showed no local recurrences and no disease-related mortality. Acral hidradenomas and digital papillary adenocarcinomas share a well-circumscribed dermal growth pattern containing solid, cystic, and tubular areas with mitotic activity and at least focal cytologic atypia. Lack of papillary structures and the diffuse positivity for p40 and p63 in the absence of S100 and SMA expression are helpful features in favor of acral hidradenoma.

PO 18120 - Eccrine poroma associated with a poroid hidradenoma in a large single lesion over the foot

Introduction: Eccrine poroma (EP) and poroid hidradenoma (PH) are rare benign neoplasms derived from eccrine sweat glands of the epithelium. Both are variants of poroid neoplasms and rarely become malignant. This report describes the clinical presentation, radiographic and pathological features as well as the treatment of a rare association of EP and PH in a large single lesion over the foot. Case Report: We present a 55-year-old male patient with a large soft tissue mass over the midfoot (approximately 7 cm in length and 4 cm width). It started as a hyperchromic black spot on the skin and has slowly grown over the last eight years. One year prior, pain increased significantly. There was no history of trauma, infection or other tumor in this part of the foot. In the physical exam, the tumor had well-defined edges, fibroelastic consistency and was not adherent to the surrounding soft tissue. Preoperative planning included radiographic exams: X-ray and magnetic resonance imaging (MRI). On the MRI, the tumor showed a low signal intensity on T1-weighted images, with heterogeneous high and low signal intensities on T2-weighted images. Strong contrast enhancement was observed after intravenous gadolinium administration in the base portion. The peripheral portion showed a low signal intensity without enhancement. We decided on total resection, and the procedure was performed in January of 2017. The surgical approach was a longitudinal dorsomedial incision over the first ray starting from the ankle joint to the distal third of the first metatarsal. The entire tumor was excised with clean margins and sent for anatomopathological analysis and histopathological examination. Histopathologic examination showed that the tumor was a poroid neoplasm consisting of both dermis (poroid hidradenoma) and epidermis (eccrine poroma) components. There were no features of malignancy. After 20 months of surgery, patient remains asymptomatic with no signs of recurrence of the tumor. Conclusion: Skin tumors must be born in mind in the differential diagnosis of a chronic mass in the foot. Surgical treatment for this type of tumor is curative and prevents recurrence and malignant change.

Poroid hidradenoma of the scalp in an immunosuppressed patient

We discuss the rare finding of what initially presented as a common subcutaneous scalp nodule. Yet, after surgical excision, the lesion was found to be a poroid hidradenoma (PH). PH is a rare variant of poroid neoplasms. PH, when observed, is commonly associated with the head and neck. However, it is rarely described in literature beyond the dermatopathologic findings. Here, we describe the clinical presentation of a unique case of a scalp PH in the setting of immunosuppression.

Mammographic and ultrasound findings in poroid hidradenoma of the breast mimicking intraductal papilloma and papillary carcinoma

Rationale:Poroid hidradenoma (PH) is a rare variant of benign sweat gland neoplasm without connection to the epidermis. This tumor presents clinically as a solitary lesion with a cystic component located in the subcutaneous layer abutting the skin. On ultrasound, it appears as a circumscribed complex cystic and solid mass abutting the dermis. The occurrence of PH in the breast is very rare. Its features overlap with intraductal papilloma and papillary carcinoma.Patient concerns:A 66-year-old woman presented with a palpable lump in her right breast.Diagnoses:Clinical examination revealed dark bluish dome-shaped nodule which presented as circumscribed round isodense mass on mammography and oval complex cystic and solid mass abutting the dermis on ultrasound. Clinically, a papillary neoplasm was suspected.Interventions:The patient underwent En bloc surgical excision including the overlying epidermis and the surrounding adipose tissue to prevent recurrence.Outcomes:A well-demarcated, non-encapsulated grayish white mass composed of a partly solid and partly cystic area was completely removed and histopathologically confirmed as PH. At the 12-month follow-up, no recurrence was evident.Lessons:PH should be considered in the differential diagnosis of a slowly growing breast mass that is bluish, cystic, and solid and abuts the dermis.

Dermatoscopy: an auxiliary resource for the diagnosis of poroid neoplasms

AbstractPoroid neoplasms are benign epithelial proliferations with eccrine sweat gland differentiation. They are a challenging diagnosis because of the clinical heterogeneity, being able to mimic several malignant neoplasms. They are classified into classic poroma, hidroacanthoma simplex, dermal duct tumor and poroid hidradenoma. Association of histological subtypes occurs in more than 25% of cases. We report a case of a combined poroid neoplasia of classical poroma and poroid hidradenoma, reviewing its dermatoscopic features.