Poroma: A Retrospective Series of 80 Patients at a Tertiary Care Hospital. / Poroma. Estudio retrospectivo de 80 pacientes en un hospital terciario.

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.

Trichilemmal cysts with proteinaceous material: A potential diagnostic pitfall.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Poroid hidradenoma in the hand: A case report and systematic review.

Poroid hidradenoma (PH) is a rare benign neoplasm of the skin appendages. There are currently no guidelines for its management, and little information available regarding the natural history, treatment options, or outcomes. Systematic literature review identified 19 cases of isolated PH. Mean age at presentation was 54 years. Male to female ratio was 3:1, and the majority of cases were in the head and neck region. One-third of lesions were painful or tender. Sizes varied from 0.11 × 0.9 × 0.2 cm (digit) to 6 cm (presternal region). Twelve cases were treated by surgical excision, while the remainder were biopsy specimens. Follow-up was reported in five cases, with a median follow-up of 1 year. No cases of local invasion or spread have been reported, although there was one case of possible recurrence identified 8 years after surgical excision. The presented case is the first to identify a PH on the hand, represents the smallest lesion to date, and was successfully treated by excision. We suggest that PHs be treated by excision and followed up for 6 to 12 months. Given one case of potential (but unconfirmed) recurrence, and no report of malignant transformation, we suggest that narrow margins may be appropriate.

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.

Giant Poroid Hidradenoma of the Forearm.

Poroid hidradenoma represents an uncommon and benign tumor originating from skin adnexa. It falls under the category of sweet duct neoplasms, along with poromas. It affects the elderly population most frequently. Typically, it emerges as a small, distinct, and painless lump beneath the skin's surface, often occurring on the head and neck regions. It is characterized by a low risk of malignant transformation. Accurate identification relies especially on histomorphological analysis considering the intricate resemblance it shares with other tumors originating from eccrine glands. Poroid hidradenoma has only recently been recognized, and only a limited number of cases have been reported in the medical literature. In this instance, we present an unusual occurrence of a giant poroid hidradenoma on the left forearm of an elderly patient.

Poroid Hidradenoma: Case Report and Comprehensive Review of the Literature.

Poroid hidradenoma (PH) is a rare benign adnexal tumor of eccrine differentiation. It is the rarest of the four described variants of poroid neoplasms. PHs characteristically share a hybrid of the architectural features of the hidradenoma, namely, tumor cells are entirely intradermal with both solid and cystic components, and the cytologic characteristics of the poroid neoplasms, containing predominantly poroid and cuticular cells. Many published reports of PH since its original discovery in 1990 state that "very few" cases of PH can be found in the literature. Here, we have identified a total of 75 published accounts of PH, including the case presented here, as well as the associated patient demographics, lesion characteristics, treatment, and outcomes. We suggest that while uncommon, PH is likely not exceptionally rare and could be an underreported diagnosis.

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.

Recent Advances on Immunohistochemistry and Molecular Biology for the Diagnosis of Adnexal Sweat Gland Tumors.

Cutaneous sweat gland tumors are a subset of adnexal neoplasms that derive or differentiate into the sweat apparatus. Their great diversity, rarity, and complex terminology make their pathological diagnosis challenging. Recent findings have revealed a wide spectrum of oncogenic drivers, several of which are of diagnostic interest for pathologists. Most of these molecular alterations are represented by gene fusions, which are shared with other homologous neoplasms occurring in organs containing exocrine glands, such as salivary and breast glands, which show similarities to the sweat apparatus. This review aims to provide a synthesis of the most recent immunohistochemical and molecular markers used for the diagnosis of sweat gland tumors and to highlight their relationship with similar tumors in other organs. It will cover adenoid cystic carcinoma (NFIB, MYB, and MYBL1 fusion), cutaneous mixed tumor (PLAG1 fusion), cylindroma and spiradenoma and their carcinomas thereof (NF-κB activation through CYLD inactivation or ALKP1 hotspot mutation), hidradenoma and hidradenocarcinoma (MAML2 fusion), myoepithelioma (EWSR1 and FUS fusion), poroma and porocarcinoma (YAP1, MAML2, and NUTM1 fusion), secretory carcinoma (ETV6, NTRK3 fusion), tubular adenoma and syringo-cystadenoma papilliferum (HRAS and BRAF activating mutations). Sweat gland tumors for which there are no known molecular abnormalities will also be briefly discussed, as well as potential future developments.

Poroid hidradenoma of the scalp in a US Veteran's Administration (VA) patient.

Poroid hidradenomas are a rare subtype of hidradenoma. A Veteran's Administration patient presented with a mobile, cystic scalp lesion. Intraoperatively the mass spontaneously ruptured. We hope clinicians will consider this entity on their differential when treating patients presenting with similar scalp lesions and intraoperative findings.

Poroma. Estudio retrospectivo de 80 pacientes en un hospital terciario / Poroma: A Retrospective Series of 80 Patients at a Tertiary Care Hospital

Introducción El poroma es un tumor anexial benigno exclusivo de la piel que tiene una predilección por la piel palmoplantar.Objetivo Analizar las características clínicas del poroma en nuestra población.Material y métodosEstudio retrospectivo de los pacientes con poroma diagnosticados entre 2002 y 2021. Se revisaron las historias clínicas para obtener los siguientes datos: edad, sexo, localización, número de lesiones, diámetro, tiempo de evolución, características clínicas de los tumores, diagnóstico clínico de sospecha, estado de los márgenes de resección, desarrollo de recidiva y tiempo de seguimiento. Las variables categóricas se compararon mediante la prueba exacta de Fisher. Las variables continuas se compararon mediante la prueba t de Student cuando se confirmó la normalidad de la distribución de datos. De lo contrario, se realizó la prueba U de Mann-Whitney. ResultadosSe incluyeron 80 pacientes con poroma (31 mujeres y 49 varones, con una edad mediana de 65,5 años y rango intercuartílico [RIC] 29 años). La mediana del tiempo medio de evolución fue de 12 meses, RIC 21 meses y la mediana del diámetro 8mm, RIC 7. Ningún paciente presentó lesiones múltiples. Las lesiones se localizaron en la cabeza y el cuello en 13 casos, en el tronco en 13, en las extremidades superiores en 11 y en las extremidades inferiores en 43. Veintitrés lesiones (28,8%) se localizaron en piel acral (palmas 5, plantas 18). La localización en el cuero cabelludo fue más frecuente en el sexo femenino (p=0,041). Las lesiones acrales fueron con mayor frecuencia eritematosas (p=0,014). Cinco pacientes presentaron recidiva local. Conclusiones Aunque los poromas son especialmente frecuentes en la piel acral, sobre todo de los pies, en la mayoría de pacientes se localizan en otras regiones anatómicas (71,3%). El aspecto clínico clásico de lesión exofítica eritematosa se observa con una mayor frecuencia en las lesiones acrales. (AU)

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 methodsRetrospective 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. (AU)

[Translated article] Poroma: A Retrospective Series of 80 Patients at a Tertiary Care Hospital / Poroma. Estudio retrospectivo de 80 pacientes en un hospital terciario

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. (AU)

Introducción El poroma es un tumor anexial benigno exclusivo de la piel que tiene predilección por la piel palmoplantar. Objetivo Analizar las características clínicas del poroma en nuestra población. Material y métodos Estudio retrospectivo de los pacientes con poroma diagnosticados entre 2002 y 2021. Se revisaron las historias clínicas para obtener los siguientes datos: edad, sexo, localización, número de lesiones, diámetro, tiempo de evolución, características clínicas de los tumores, diagnóstico clínico de sospecha, estado de los márgenes de resección, desarrollo de recidiva y tiempo de seguimiento. Las variables categóricas se compararon mediante la prueba exacta de Fisher. Las variables continuas se compararon mediante la prueba t de Student cuando se confirmó la normalidad de la distribución de datos. De lo contrario, se realizó la prueba U de Mann-Whitney. Resultados Se incluyeron 80 pacientes con poroma (31 mujeres y 49 varones, con una edad mediana de 65,5años y rango intercuartílico [RIC] de 29 años). La mediana del tiempo medio de evolución fue de 12meses, RIC 21 meses, y la mediana del diámetro 8mm, RIC 7. Ningún paciente presentó lesiones múltiples. Las lesiones se localizaron en la cabeza y en el cuello en 13 casos, en el tronco en 13, en las extremidades superiores en 11 y en las extremidades inferiores en 43. Veintitrés lesiones (28,8%) se localizaron en piel acral (palmas 5, plantas 18). La localización en el cuero cabelludo fue más frecuente en el sexo femenino (p=0,041). Las lesiones acrales fueron con mayor frecuencia eritematosas (p=0,014). Cinco pacientes presentaron recidiva local. Conclusiones Aunque los poromas son especialmente frecuentes en la piel acral, sobre todo de los pies, en la mayoría de pacientes se localizan en otras regiones anatómicas (71,3%). El aspecto clínico clásico de lesión exofítica eritematosa se observa con una mayor frecuencia en las lesiones acrales. (AU)

Clinicopathological analysis of 384 cases of poroid neoplasms including 98 cases of apocrine type cases.

We examined 384 cases of poroid neoplasms. Most cases (n = 279, 72.7%) exhibited the features of only one subtype. One hundred and ninety-eight cases (51.6%) showed only the features of poroma (P), 20 (5.2%) hidroacanthoma simplex (HS), five (1.3%) dermal duct tumor (D) and 56 (14.6%) hidradenoma (HA). Composite tumors of those four subtypes were observed in 105 cases (27.3%). In the trunk and lower extremities, lesions with the features of P were observed at higher rates than other sites. Those of HS and D were more frequently observed in the lower extremities. Those of HA were seen at higher rates in the scalp, face, neck and genitalia. Ninety-eight cases (25.5%) showed decapitation secretion and diagnosed as apocrine type lesion. Apocrine type lesions were frequently observed in the lesions on the genitalia (40.0%), scalp (31.8%) and trunk (31.1%), whereas at lower rates in those on the neck (21.4%) and lower extremities (24.0%). In apocrine type cases, the lesions were located more frequently on the scalp and trunk than non-apocrine type, whereas were less frequent on extremities. The rate of apocrine type lesions in the cases with only one subtype (19.7%) was lower than that of those with composite tumors (41.0%). In the apocrine type (43.9%), composite tumors are more frequent than in the non-apocrine type (21.7%). In D (40.8%) and HA (32.3%), apocrine type lesions were more frequently observed than other subtypes. In conclusion, it should be noted that a quarter of poroid neoplasms are composite tumors and/or show apocrine differentiation.

Hidradenocarcinoma: A Rare Sweat Gland Neoplasm Presenting as Small Turban Tumor of the Scalp.

Hidradenocarcinomas are very rare malignant sweat gland tumors that possess an infiltrative and/or low metastatic potential. Here we describe an interesting case of hidradenoma on the fronto-parietal region of the scalp of an elderly female, part of which had developed carcinomatous changes, infiltrating up to the pericranium. She developed intense itching, pain, spontaneous ulceration and rapid increase in the size of the tumor correlating with the expression of malignant behavior of the neoplasm. An initial incision biopsy suggested features of benign poroid hidradenoma, while the histology from the excised tumor exhibited a fairly well circumscribed epithelial neoplasm in dermis consisting of interconnected nodules as well as differentiated ducts, the neoplastic cells showing mild pleomorphism of nuclei, mitotic figures and abundant pale cytoplasm. Clefts, sclerotic stroma and foci of necrosis en mass were also seen. The final diagnosis was a well differentiated and slow growing hidradenocarcinoma. The tumor recurred locally despite total excision.