A rare case of hidradenocarcinoma with anaplastic and invasive features arising from a nodulocystic hidradenoma.

A 91-year-old man presented with a cutaneous left abdominal mass. The mass was longstanding (over 5 years) and slow-growing. Examination revealed a violaceous, multinodular, and exophytic non-tender mass surrounded by patchy erythema. Excisional biopsy was performed and revealed a nodular and cystic dermal proliferation of predominately basaloid cells with focal duct formation, surrounded by prominent hyalinized stroma. The superficial portion of the mass was identified as a nodulocystic hidradenoma. Along the deep aspect and in association with the benign hidradenoma, sheets of markedly atypical epithelioid cells invaded the surrounding tissue, consistent with malignant transformation. Perineural and lymphovascular invasion were seen among areas with anaplastic features. This case supports that some hidradenocarcinoma originates from benign counterparts, and as such, ample sampling is required to definitively exclude a more sinister diagnosis. Diagnostic, prognostic, histopathological, and molecular characteristics, and current knowledge limitations are briefly discussed.

Clear cell hidradenoma of the breast with MAML2 gene rearrangement.

Clear cell hidradenoma is a rare benign tumor of the breast, its origin and pathogenesis are controversial. We have experienced a case of breast clear cell hidradenoma with mastermind like transcriptional coactivator 2 (MAML2) gene rearrangement. The patient found a painless mass with a hard texture in the left breast areola without nipple discharge. Microscopically, the tumor was cystic and solid, locally arranged in a glandular structure, covered by single cuboidal cells; it was composed of clear cells, epidermoid cells, and basaloid cells; there were no necrosis or mitotic figures. Immunohistochemical staining showed that the tumor cells positively expressed low-molecular cytokeratin 7, low-molecular cytokeratins (Cam5.2), high-molecular cytokeratin 5/6, cytokeratin 14, CD117, and p63; and did not express calponin, and smooth muscle myosin heavy chain. The cuboidal cells were positive for SOX10 but negative for p63. Additionally, periodic acid-Schiff reaction showed purple-red granules in the tumor cytoplasm, but Alcian blue staining showed no blue mucus in the cytoplasm. The split signals of MAML2 gene were detected by fluorescence in situ hybridization. Subtle histological and immunophenotypical differences may help to distinguish breast clear cell hidradenoma from common breast tumors. Furthermore, the MAML2 gene rearrangement may be a molecular genetic characteristic of breast clear cell hidradenoma.

Hidradenoma of Pinna -Report of a Rare Case at a Rare Site.

There are various reports of hidradenoma of cartilaginous part of external auricular canal (ear), but the documented evidence of occurrence of hidradenoma of pinna is seldom available in world literature, hence we report one such case. The patient was a 45-year female with a lump in the region of the posterior aspect of the pinna of the right ear for the past 6 months. No history of pain except for serous discharge from the lump. FNAC of the lump showed histological feature of hidradenoma. Wide surgical excision of the lump was done under local anaesthesia and sent for histopathological examination. HPE confirmed the diagnosis of Hidradenoma. She is on follow up, till date no sign of recurrence.

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.

A Rare Case of Ectopic Hidradenoma Papilliferum of the External Auditory Canal.

Hidradenoma papilliferum (HP) is a benign adnexal tumor, commonly affecting the anogenital region of middle-aged women. Clinically, HP typically presents as a slow-growing, unilateral, well-circumscribed, smooth skin-colored cystic dermal nodule, usually growing less than 1 cm in size. Reports of ectopic HP are exceedingly rare but have been identified in areas containing modified apocrine gland structures, most commonly on the head and neck, and have included ceruminous glands of the external ear canal, the Moll glands of the eyelid, mammary glands of the breast, maxillofacial region and areas on the scalp. To the best of our knowledge, there is only one case of ectopic HP located on the external ear canal reported in English literature. We present a second case of draining ectopic HP located on the conchal bowl of the external ear canal.

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.

Vulvar Hidradenoma Papilliferum.

Aim: This study examines the clinical and pathological characteristics, immune profile, histological occurrence, diagnosis, and differential diagnosis of vulvar hidradenoma papilliferum. Methods: An analysis was conducted on clinical data, histological patterns, and immunohistochemical findings from 45 cases of vulvar hidradenoma papilliferum, and relevant published articles were reviewed. Simultaneously, high-risk HPV typing was performed on these 45 cases. Results: The 45 cases of vulvar hidradenoma papilliferum displayed tumor sizes ranging from 0.3 to 2.0 cm and were observed to be pink or red in appearance. Vacuolated cytoplasm, large abnormal nuclei, distinct nucleoli, and scattered eosinophilic luminal secretions were observed in the glands. Positive staining for CK7 and progesterone receptor (PR) with focal mammaglobin and GCDFP-15 expression was found through immunohistochemistry. CK20 staining was noted as negative. Conclusion: Hidradenoma papilliferum is a rare benign tumor that originates in secretory glands. The diagnosis of this condition is aided by gross and immunohistochemical results, and differentiation from other conditions is necessary.

Remote Possibility of Post Aural Swelling as Nodular Hidradenoma: A Case Report.

A 30-year-old female patient presented with swelling over the left post aural region of 6 months duration which gradually increased in size. Cutaneous examination: A solitary, non-tender, mobile swelling of variable consistency over the post aural region. Dermoscopic examination: Revealed white and red areas. Diagnosis of nodular hidradenoma was made by histopathological examination.

Recurrent Malignant Sweat Gland Tumor.

Malignant sweat gland tumors are very rare. Hidradenocarcinoma is an uncommon malignancy arising from the intradermal ductal epithelium of eccrine sweat glands, usually in the sun-exposed parts of the body. It usually arises de novo but may develop from a benign hidradenoma. The diagnosis of hidradenocarcinoma is clinically challenging as it presents with varied consistency and clinically mimics other skin lesions such as chronic sebaceous cysts or epidermoid cysts. Hidradenocarcinoma is a highly aggressive tumor with a tendency for regional and distant spread. It is difficult to treat hidradenocarcinoma as it has high rates of morbidity and mortality and a very high incidence of recurrence. Here, we report a rare case of a 45-year-old woman who presented with a recurrent lump over the left arm diagnosed as primary hidradenocarcinoma.

Ancillary immunohistochemical and molecular testing in the classification of cutaneous sweat gland/duct neoplasms: A validation study with emphasis on histomorphologic correlation and pathological diagnosis.

Sweat gland neoplasms represent a challenging area of dermatopathology, as they are relatively uncommon and often histopathologically complex. Recent studies have uncovered distinct immunohistochemical and molecular profiles in several sweat gland neoplasms, including digital papillary adenocarcinoma (DPA), papillary eccrine adenoma/tubular apocrine adenoma (PEA/TAA), poroid family tumors (PFT)/porocarcinoma, and clear cell hidradenoma (CCH)/clear cell hidradenocarcinoma (CCHCa). To further evaluate the diagnostic utility of ancillary studies in various sweat gland neoplasms, we performed an independent validation study in a cohort of patients with acral and non-acral tumors (9 DPA, 8 PEA/TAA, 13 PFT, 5 porocarcinoma, 23 CCH, 7 CCHCa, 6 sweat gland carcinoma not otherwise specified). p63 immunohistochemistry (IHC) demonstrated a myoepithelial pattern in 8/8 DPA and 4 of 4 tested PEA/TAA cases, and showed a ductal pattern in all tested PFT/porocarcinoma and CCH/CCHCa cases (42/42). All PEA/TAA (8/8) cases were positive for BRAF V600E IHC. 5 of 12 tested PFT and 5/5 porocarcinoma cases showed either positive staining with NUT IHC or harbored YAP1::NUTM1 fusion gene by RNA sequencing. MAML2 fluorescence in situ hybridization (FISH) was positive in all CCH and CCHCa cases (23/23 and 7/7, respectively). Our results further support the usefulness of appropriate ancillary studies in precise classification of sweat gland tumors, which may be routinely applied in diagnostic pathology practice when morphologic evaluation is in doubt.

Hidradenoma nodular maligno / Malignant Nodular Hidradenoma

Introducción: El hidradenoma nodular maligno es un tumor maligno de glándula sudorípara ecrinas, poco común, considerada una lesión de diferenciación anexial ecrinas, que generalmente surge de nuevo, aunque se han descrito unos pocos casos surgidos sobre un hidradenoma nodular. Es decir, representa la contrapartida maligna del hidradenoma nodular. Objetivo: Dar a conocer la presentación de un caso, dada la inusual aparición de esta entidad, con revisión de los criterios para su diagnóstico. Caso clínico: Se informa el caso de un hombre de 74 años de edad con una neo formación en la región parietal derecha del cuero cabelludo. Conclusiones: Debemos pensar en un hidradenoma nodular maligno ante un tumor solitario, firme o fluctuante, infrecuente en el cuero cabelludo, con curso agresivo, recurrencias y metástasis ganglionares y confirmar su diagnóstico con el estudio inmunohistoquímico(AU)

Introduction: Malignant nodular hidradenoma is a rare malignant eccrine sweat gland tumor considered a lesion of eccrine adnexal differentiation, which usually arises again, although a few arising cases on nodular hidradenoma have been described. In other words, it represents the malignant counterpart of nodular hidradenoma. Objective: To report a case, given the unusual occurrence of this entity, with a review of the criteria for its diagnosis. Case report: We report the case of a 74-year-old man with a neoformation in the right parietal region of the scalp. Conclusions: We should consider a malignant nodular hidradenoma when faced with a solitary, firm or fluctuant tumor, rare in the scalp, with aggressive evolution, recurrences and lymph node metastasis, and confirm its diagnosis with immunohistochemical study(AU)

Hidradenoma nodular maligno / Malignant nodular hydradenoma

RESUMEN El Hidradenoma nodular maligno o Hidradenocarcinoma es un tumor poco frecuente, derivado de las glándulas sudoríparas ecrinas. Puede surgir de novo o por la transformación de su contraparte benigna. Estos tumores son de crecimiento lento, comportamiento agresivo, con alta incidencia de recurrencias y posibilidad de metástasis. Su prevalencia es en la población adulta, y su pronóstico, incierto. El tratamiento de elección de estos tumores es la escisión quirúrgica con márgenes amplios.

ABSTRACT The Malignant nodular Hydradenoma or Hydradenocarcinoma is a rare tumor, derived from the eccrine sweat glands, may arise de novo or by the transformation of its benign counterpart. These tumors are slow growing, aggressive behavior, with a high incidence of recurrences and the possibility of metastasis; its prevalence being in the adult population, and its prognosis is uncertain. The treatment of choice for these tumors is surgical excision with wide margins.

Perianal hidradenoma papilliferum / Hidradenoma papilífero perianal

ABSTRACT Hidradenoma papilliferum is a benign cystic tumor originated in apocrine sweat glands of the anogenital region. It is common in vulvar topography and rare in the perianal region. A well-documented case of a patient with slow-growing perianal nodulation without pain or other symptoms is reported. The histological study shows a hidradenoma papilliferum. The article reviews the topic and discusses the importance of the differential diagnosis of proctological conditions. A biopsy is mandatory in anal lesions of unusual presentation.

RESUMO O hidradenoma papilífero é um tumor cístico benigno originado nas glândulas sudoríparas apócrinas da região anogenital, sendo comum em topografia vulvar e raro na região perianal. Relata-se um caso bem documentado de paciente com nodulação perianal de crescimento lento, sem dor ou outros sintomas, cujo estudo histológico revelou se tratar de hidradenoma papilífero. O artigo revisa o tema e discute a importância do diagnóstico diferencial das afecções proctológicas, sendo a biópsia obrigatória em lesões anais de apresentação não-usual.

Localización inusual del hidradenoma papilífero / Unusual location of the papilliform hydradenoma

El hidradenoma papilífero es una tumoración benigna, rara, generalmente localizada en la región vulvar o perineal siendo la región perianal una localización poco frecuente. Su asociación con enfermedades de transmisión sexual y el carcinoma ductal es controvertida; es importante realizar el estudio histopatológico de cualquier tumoración en esta zona. Se reporta el caso de una paciente de 49 años de edad, con un nódulo en la región perianal de 2 años de evolución; el estudio histopatológico confirmó el diagnóstico de hidradenoma papilífero. (AU)

The papilliferous hidradenoma is a benign, rare tumor, usually located in the vulvar or perineal region and the perianal region is a rare site. Its association with sexually transmitted diseases and ductal carcinoma is controversial. It is important to perform the histopathological study of any tumor in this area. The case of a 49-year-old patient with a nodule in the perianal region of 2 years of evolution is reported. The histopathological study confirmed the diagnosis of papilliferous hidradenoma.

Hidradenoma papilífero: reporte de tres casos y revisión de la literatura / Hidradenoma papilliferum: report of three cases and review of the literature

El hidradenoma papilífero es un tumor infrecuente que ocurre casi de manera exclusiva en la región anogenital de las mujeres, sin embargo se han descrito casos de hidradenomas papilíferos ectópicos. Las lesiones generalmente son asintomóticas de crecimiento lento, eritematosas, firmes, y se presentan como un nódulo bien delimitado. Reportamos tres casos de hidradedoma papilífero en región vulvar, diagnosticados entre 2009 y 2010 en el Hospital Universitario de Caracas. En los tres casos se presente una lesión única, nodular, en labio mayor, con diámetro < 10 mm, renitente, nacarada, no pruriginosa. Hasta la actualidad se ha reportado solo un caso en laliteratura venezolana

Hidradenoma papilliferum is a rare tumor that occurs almost exclusively in the anogenital region of women, however has been reports ectopic hidradenoma papilliferum. The lesions are usually asymptomatic, slow-growing, erythematous, firm, and are presented as awell-defined nodule. We report three cases of vulvar hidradenoma papillifirum, diagnosed between 2009 and 2010 at the Hospital Universitario de Caracas. In all three cases was presented as a single, nodular lesion in labia major with a diameter < 10mm, firm, pearly, not itchy. Until now it has been reported only one case in Venezuelan literature