A study of histopathologic spectrum of nodular hidradenoma. Am J Dermatopathol. 2012;34:461-470. [PMID: 21993337 DOI: 10.1097/dad.0b013e31821a4d33]

Pseudosquamous Adenocarcinoma of the Lung: Clinicopathologic and Immunohistochemical Study of 10 Cases

Pseudosquamous adenocarcinoma of the lung is an unusual morphologic variant of poorly differentiated non-small cell lung carcinoma that superficially resembles a squamous cell carcinoma. We have examined 10 cases of these tumors in 4 women and 6 men, aged 47 to 93 years. The tumors were all peripheral and measured from 1.5 to 5.5 cm. All cases were characterized by solid nests of large polygonal tumor cells containing atypical nuclei with abundant cytoplasm and sharp cell borders, adopting a pavement-like architecture that simulated squamous cell carcinoma. Some cases demonstrated intracytoplasmic hyaline inclusions suggestive of keratinization. The nests of tumor cells often showed central comedo-like areas of necrosis. Intercellular bridges were not seen in any of the cases. The tumors often displayed marked clearing of the cytoplasm enhancing their epidermoid appearance. In 4 cases, the solid pseudosquamous areas were seen to merge with a focal lepidic adenocarcinoma component, and in 1 case, abortive microscopic foci of acinar differentiation were also noted within the tumor. One case showed focal sarcomatoid spindle cell areas. The tumor cells were negative for p40 and CK5/6 and labeled with TTF1 or Napsin-A, confirming an adenocarcinoma phenotype. Clinical follow-up information was available in 8 patients; 6 patients died of their tumors between 6 months to 11 years after diagnosis (mean: 3.1 y). One patient died of complications related to surgery and one patient with a low-stage tumor died at 27 years from other causes. Solid pattern adenocarcinomas can be confused for squamous cell carcinoma and may require immunohistochemistry to determine their true phenotype.

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.

Two blue nodules on the right leg

Hidradenoma is an asymptomatic benign sweat gland tumour with apocrine or eccrine differentiation. The most common dermoscopic features are bluish or pinkish homogeneous areas, white structures and vascular structures such as arborizing telangiectasias and polymorphous atypical vessels, mimicking other malignant tumours such as basal cell carcinoma and melanoma. As this tumour is a great masquerader, one should keep in mind hidradenoma in the differential diagnosis, when a blue colour is seen on dermoscopy. Owing to the risk of hidradenocarcinoma development on a pre-existing hidradenoma, the management of this tumour is surgical excision.

Apocrine cystadenoma: A long-standing apocrine hidrocystoma with an adenomatous proliferation

BACKGROUND

Apocrine cystadenoma is a rare, benign adenomatous cystic neoplasm, the pathogenesis of which is not fully understood. We sought to characterize the clinical, dermatoscopic, and histopathologic features of apocrine cystadenoma and its relationship to hidrocystoma.

METHODS

We retrospectively analyzed cases of apocrine cystadenoma and hidrocystoma retrieved from the dermatopathology laboratory information system.

RESULTS

Of the 350 cases apocrine cystic lesions, 13 cases of apocrine cystadenomas met the inclusion criteria. The age ranged from 20 to 84 years with an average of 64 years. They were long-standing (duration 3-15 years), slow-growing, large tumors usually found on the scalp. Dermatoscopy accentuated translucent light to dark blue color and prominent vessels that were present more at the periphery. All lesions were multilocular with columnar to cuboidal lining and decapitation secretion. A large portion of the lesion consisted of a simple nonproliferative epithelial lining, identical to that observed in apocrine hidrocystomas, while the proliferative adenomatous component made up a smaller portion with two patterns: (1) tubular proliferation, which either protruded into the cystic cavity or expanded outward peripherally, or (2) papillary projections, which were multiple layers thick with fibrovascular core, sometimes accompanied by tubular proliferation. Immunohistochemical stains showed strong staining for p40 and a sparse number of cells stained for Ki-67 and p53.

CONCLUSIONS

The long duration of the lesion and the large areas of simple apocrine epithelial lining suggest that apocrine cystadenomas arise from long-standing apocrine hidrocystomas. However, the retrospective nature of the study from a single institution is a limitation.

An Unusual Presentation of Nodular Hidradenoma

Benign adnexal neoplasms are quite a common occurrence in adults, especially in the head and neck region. They raise suspicion for malignancy if there are red flag signs like rapid increase in size, pain, ulceration or recurrence. We hereby report a case of a middle-aged gentleman who consulted our surgical OPD with right-sided neck swelling, which was initially thought to be a dermoid cyst; on further evaluation, found to be a dermal sweat gland tumour with features of nodular hidradenoma. The point that is of interest but coincidence to note is that this swelling was preceded by a minor trauma. Characterising these swellings using simple imaging and pathological investigation modalities is important to study their behavioural pattern and add the same to our existing database. This will also help the treating surgeons to keep in mind the possibility of occurrence of such histologies in soft tissue swellings when they present with uncommon clinical features, instead of brushing them aside as the common epidermal or dermoid cysts. Incidence of malignancy is almost nil in nodular hidradenoma, which when found, is attributed to poor surgical clearance; hence the prudence to operate with adequate clearance is extremely significant in preventing the transformation of a mole into a mountain.

Eccrine Hidradenoma of the Nasal Vestibule: A Rare Clinical Entity

Eccrine hidradenoma is a relatively rare benign tumor of sweat gland origin but with possible malignant transformation. It usually consists of solitary, well-demarcated papules or nodules covered with normal skin. Common sites of involvement are the scalp, face, limbs, and anterior trunk. Although the lining of the nasal vestibule includes hair follicles, sebaceous glands, and sweat glands, an eccrine hidradenoma originating in the nasal vestibule has yet to be reported. Herein, we describe a rare clinical presentation of nasal eccrine hidradenoma, treated successfully using a transnasal endoscopic approach.

Prognostic analysis of hidradenocarcinoma: a SEER-based observational study

BACKGROUND

Hidradenocarcinoma is a rare malignancy of sweat gland differentiation. Published literature has reported that hidradenocarcinoma has a high recurrence and metastasis rate, and the prognosis is extremely poor. However, the sample sizes included in these studies are insufficient, and therefore, the findings are doubtful.

MATERIALS AND METHODS

Clinicopathological characteristics and survival data of 289 hidradenocarcinoma patients were extracted from the SEER database (covering 18 registries, 2000-2018) released in July 2021. The distribution of clinicopathological characteristics was compared using the Pearson chi-square test. Overall survival (OS) and cancer-specific survival (CSS) were analysed using the log-rank test and univariate analysis.

RESULTS

The primary site of hidradenocarcinoma in 121 patients was located in the head and neck, accounting for 41.9%, and the others were located in the trunk and limbs. For hidradenocarcinoma, the mean OS and CSS were 164 months and 165.9 months, respectively; the 10-year OS rate and CSS rate were 60.2% and 90.5%, respectively. Survival analysis showed that the primary site, sex, age, race, histologic grade, stage, and surgery are not associated with hidradenocarcinoma patients' OS or CSS. For head and neck hidradenocarcinoma or trunk and limbs hidradenocarcinoma, sex, age, race, histologic grade, AJCC stage, and primary site surgery are still not related to prognosis. Tumour size is correlated with patients' OS rather than CSS.

CONCLUSIONS

Hidradenocarcinoma is a malignant tumour with a good prognosis, which is different from previous views. Tumour size is inversely proportional to patients' overall survival time affecting the OS and CSS of patients. Improving health awareness, initial histological examination and timely surgery are the keys to improving the prognosis.

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 polymorphism microarray. 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 sensitive but 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.

Nodular Hidradenoma of the Lower Limb Impersonating as Sebaceous Cyst in a Young Female

Adnexal tumors possess a remarkable capacity for morphological diversity and often present with nonspecific clinical presentations. Definitive diagnosis is made on histopathology with categorization based on the predominant morphological component. We present a case of a 31-year-old woman, with a swelling in the upper one-third of the right leg suspected clinically to be an infected sebaceous cyst. Histopathological examination clinched the diagnosis of a nodular hidradenoma. We wish to present this case not only for its uncommon clinical presentation but also for the diverse spectrum of histomorphological features that can be exhibited by this tumor. The case also emphasizes to surgeons the importance of complete surgical resection given the chances of recurrence and rare cases of malignant transformation associated with this entity.

A rare case of Hidradenoma of the lower lip

Hidradenoma are rare benign tumors with eccrine or apocrine differentiation that most often presents as a small, firm, solitary dermal nodule. At times, hidradenoma shows striking cytologic and histologic similarity to other neoplasms, including its malignant counterpart, hidradenocarcinoma. We present the first reported case of benign hidradenoma of the lower lip. The case illustrates important diagnostic features of hidradenoma and discusses the current understanding of its malignant potential and the appropriate management of such lesions.

A Case of Scapular Hidradenoma Treated as a Keloid

Hidradenomas are relatively rare benign tumors in the dermis that differentiate into eccrine or apocrine sweat glands. They often present as round or oval nodules and vary in color. Generally, they occur in the head and neck region. Keloid scars are often red, elevated lesions that are caused by chronic inflammation in the reticular dermis. These scars demonstrate a preference for high skin-tension sites, including the scapular region. Herein, we describe a case of a dark red hidradenoma on the scapular region with a high incidence of acne surrounding the lesion area that was initially diagnosed as an acne-initiated keloid. However, local steroid injection did not cure the lesion. After excision, histopathology revealed typical findings for hidradenoma, namely mucinous, polygonal, and clear cell composition. In some cases, as presented it may be challenging for clinicians to differentiate between hidradenoma and keloid due to the similar clinical features. Thus, hidradenoma should be taken in consideration as a differential diagnosis when encountering steroid-refractory keloid-like lesions. Moreover, early biopsy or surgical resection should be considered.

Perineal Clear Cell Hidradenoma: A GATA3-positive Neoplasm With Potential for Misdiagnosis

We report a case of clear cell hidradenoma of the perineum that was initially misinterpreted as a papillary urothelial carcinoma, either metastatic or of Bartholin gland origin, on initial excisional biopsy. The misinterpretation may have been due to the pseudopapillary architecture and GATA3-positivity of the biopsy tissue. Clear cell hidradenomas often show a range of histologic growth patterns and cellular differentiation and are one of many tumors that react immunohistochemically with GATA3. Although rare, these tumors can occur in the genital region and can mimic malignant tumors such as metastatic renal cell carcinoma and carcinomas of the genitourinary tract. This report details the morphologic and immunohistochemical pitfalls that make accurate diagnosis of clear cell hidradenoma in this unusual location challenging.

Rapidly Enlarging Hidradenoma of the Eyelid

Hidradenoma is a rare benign neoplasm, with few cases reported to involve the eyelid. When affecting the eyelid, hidradenomas may mimic other benign or malignant lesions. Rarely, a benign hidradenoma may transform into a malignant hidradenoma and metastasize. The authors present a case of a benign hidradenoma arising from the eyelid, presenting with rapid growth, ulceration, and bleeding, suggestive of a malignant lesion.

Poroid Hidradenoma: A Two-Case Report and Literature Review

Poroid hidradenoma (PH) is a rare benign tumor that shows differentiation of the eccrine sweat gland. It occurs mainly in adults, presenting as a 0.5 to 2 cm-sized intradermal nodule, mostly on the head, extremities, trunk and neck. We report two rare cases of PH, one on the face and the other on the heel. The first patient was a 50-year-old male who had a solitary, skin-colored nodule on his right temple for 6 months. The second patient was a 67-year-old female who presented with a solitary, bean-sized, tender nodule on her left heel for 1 year. The common histological examination finding was a well-circumscribed tumor composed of solid portions and large cystic spaces in the center. The tumor cells consisted of small, monomorphic poroid cells and large cuticular cells in both cases. To our knowledge, only few cases of PH have been reported. Herein, we report two rare cases of PHs with literature review.

An unusual presentation of a nodular hidradenoma: A case report and review of the literature

Nodular hidradenoma is a rare benign adnexal tumor. It is most frequently encountered in the head and neck region, trunk, and extremities. This tumor exhibits a high recurrence rate, and an association with malignancy.Many names have been used to describe this pathology.We report the case of a nodular hidradenoma in a 30-year-old moroccan woman who presented with a 2-year history of a swelling in her right preauricular region. Histological examination revealed the typical appearance of a nodular hidradenoma. The tumor was excised and one year after the initial presentation, there was no sign of recurrence. We emphasize the importance of wide surgical excision with appropriate margins to prevent local recurrence. A close follow up of the patients is recommended.

Clear cell hidradenoma of the hand: A case report in an 83-year old patient

INTRODUCTION

Clear cell hidradenoma (CCH) is a superficial adnexal tumor of the sweat glands. It generally appears on the trunk or scalp and is uncommon on the upper and lower limbs; it is extremely rare on the hand. CCH tend to be benign, with low malignancy risk. Treatment is based on complete surgical excision. We report a rare case of a CCH of the palm of the hand in an 83-year old patient.

PRESENTATION OF CASE

An 83-year old male patient presented with a small mass on the palmar surface of his left hand, which was progressively increasing over 5 years. The tumor was surgically excised after sonography and sent for histologic examination, based on which diagnosis of CCH was made. Three months after surgery, the patient had no recurrence and was symptom free.

DISCUSSION

CCH is a rare tumor of the distal extremities and to the best of our knowledge, only one case of this tumor on the hand has been reported. Our case represents a rare CCH located at the palm of the hand, which was successfully surgical excised without recurrence. Therefore, CCH needs to be considered in the differential diagnosis when encountering masses on the distal extremities. Hidradenocarcinoma is the malignant variant that arises from the same cells.

CONCLUSION

We report the second case of CCH on the palmar surface of the hand. Treatment of choice is surgical excision, followed by histological analysis and close follow-up for recurrence.

Salivary gland hyalinizing clear-cell carcinoma with cutaneous metastasis: A rare and deceptive tumor

Clear-cell carcinoma (CCC) is an uncommon malignant tumor of minor salivary glands. It characteristically has a low-grade morphology and a favorable outcome by most reports. An EWSR1-ATF1 fusion can be detected in the majority of cases. We present a rare case of CCC, which had an aggressive course with the development of cutaneous metastases. Practicing dermatopathologists should be aware of this tumor given its low-grade appearance and histopathologic resemblance to other primary cutaneous adnexal and metastatic neoplasms.

Case Report and Literature Review of Nodular Hiradenoma, a Rare Adnexal Tumor That Mimics Breast Carcinoma, in a 20-Year-Old Woman

Nodular hidradenoma is an uncommon cutaneous adnexal tumor arising from sweat glands. In the skin, it usually presents as a solitary dermal nodule; excision is curative in most cases. In rare instances, it may present as a breast mass and can mimic breast carcinoma clinically and radiologically, causing diagnostic dilemmas for the treating physician and pathologist. Herein, we discuss a case of nodular hidradenoma in a 20-year-old Hispanic woman as a rapidly growing mass in the breast that mimicked breast carcinoma. We discuss the rare presentation of this uncommon tumor and the differential diagnosis of this entity, as well as the results of our literature review on the topic.

Malignant sweat gland tumor of breast arising in pre-existing benign tumor: A case report

BACKGROUND

Sweat glands belong to skin appendages. Sweat gland tumors are uncommon, especially when they occur as malignant tumors in the breast. We report a case of malignant sweat gland tumor of the breast, including imaging and pathological findings.

CASE SUMMARY

A 47-year-old woman visited our hospital with a non-tender palpable lesion in her left breast. The lesion had not shown changes for 10 years. However, it recently increased in size. Sonography showed a well circumscribed cystic lesion with internal debris and fluid-fluid level. Magnetic resonance imaging showed a well circumscribed oval mass with T1 hyper-intensity compared to muscle and T2 high signal intensity. There was a small enhancing mural component in the inner wall of the mass. The tumor was resected. Its pathologic result was a malignant transformation of benign sweat gland tumor such as hidradenoma. The lesion was treated with excision and radiation therapy. At 1-year follow up, there was no local recurrence or metastasis in the patient.

CONCLUSION

In the case of a rapid growing cystic mass in the nipple and subareola, it is necessary to distinguish it from a malignant sweat gland tumor.

Solid Variant of a Proliferative Apocrine Hidrocystoma

A cystic lesion of the eyelid margin in a 37-year-old man was diagnosed clinically as an apocrine hidrocystoma, a common lesion in that location. Histopathologic examination confirmed the presence of a hidrocystoma but also disclosed an extensive proliferation of bland epithelial cells arising from the inner layer of the cyst. The authors further characterized this unique occurrence on the spectrum of Moll gland eyelid tumors by immunohistochemical analysis.

Sonographic Characteristics of Apocrine Nodular Hidradenoma of the Skin

Nodular hidradenomas are benign sweat gland-derived tumors that can produce clinical and dermatoscopic misdiagnoses. Histologically, these tumors can be classified into eccrine and apocrine subtypes. We present the sonographic characteristics of 6 cases of apocrine nodular hidradenomas, which, to our knowledge, is so far the largest series reported. A detailed sonographic analysis included layers, body location, shape, diameters, echostructure patterns, and vascularity. Two sonographic signs not previously reported in these or other common dermatologic lesions were detected: "snow falling" and "fluid-fluid level." The sonographic characteristics of apocrine nodular hidradenomas can support their earlier and more precise diagnosis.

Case for diagnosis. A bluish nodule on the scalp

Acrospiroma, also known as hidradenoma, is a rare cutaneous tumor that has several histological characteristics. As a consequence, a high index of suspicion is necessary for its diagnosis. Here we report a case that illustrates the importance of a good clinical-pathologic correlation in order to recognize this disease.

Nodular hidradenoma arising on the site of a BCG scar

Hidradenomas are tumours that arise from the adnexal structures, both eccrine and apocrine and are histologically benign. The tumours that arise from eccrine differentiation are known as poroid hidradenomas and when they arise from the apocrine glands they are called nodular hidradenomas. In our centre a 13-year-old boy presented with a slow-growing, painless erythematous fungating nodule on the left upper arm over a period of 18 months at the site of the BCG vaccination. The nodule was surgically excised and sent for histopathological examination, leading to a diagnosis of nodular hidradenoma. This case is presented to highlight its rarity, together with its clinical features that were suggestive of malignancy but proved ultimately to be benign.