Characteristic Clinical and Dermoscopic Features of Nonvolar Poroma.

BACKGROUND: A poroma typically presents as a solitary, pink-to-red papule or nodule in acral volar areas. However, in nonvolar areas, this typical clinical feature (TCF) can be difficult to identify. OBJECTIVE: We aimed to compare clinical and dermoscopic characteristics between nonvolar poroma (NVP) and volar (ie, typical) poroma (VP). METHODS: We assessed the clinical and dermoscopic characteristics of 40 patients with poromas who were divided into the NVP and VP groups. RESULTS: Of the 40 patients, 20 (50.0%) were allocated to the NVP group and 20 (50.0%) to the VP group. Pigmented variants were more common in the NVP group than in the VP group (60.0% vs 5.0%). The TCF of poroma was observed less frequently in the NVP than the VP group (45.0% vs 85.0%). Approximately one-third (30.0%) of patients with NVP received an initial clinical diagnosis of skin cancer. Dermoscopic patterns associated with melanoma or basal cell carcinoma were more common in the NVP group than in the VP group (65% vs 30%). CONCLUSIONS: Skin cancer-associated clinicodermoscopic features were more frequently observed in patients with NVP, who simultaneously lost dermoscopic patterns associated to poromas and acquired those associated with skin cancer, than those with VP.

Tubulopapillary Cystic Adenoma With Apocrine Differentiation: A Unifying Concept for Syringocystadenoma Papilliferum, Apocrine Gland Cyst, and Tubular Papillary Adenoma.

Syringocystadenoma papilliferum (SCAP), apocrine gland cyst (AGC, also called apocrine hidrocystoma or apocrine cystadenoma), and tubular papillary adenoma (TPA) with apocrine differentiation are defined as proliferations of apocrine epithelium with myoepithelial cells. At Sapporo Dermatopathology Institute, we retrieved 308 benign neoplastic lesions diagnosed as SCAP, AGC, or TPA and combinations of these entities. Among the 308 lesions, 202 (66%) exhibited features of only one type, of which 144 (47%) were AGC, 39 (13%) were TPA, and 19 (6%) were SCAP. The other 106 lesions (34%) had features of 2 or more types, including 56 lesions that were AGC + TPA (18%), 2 that were AGC + SCAP (1%), 34 that were TPA + SCAP (11%), and 14 that were AGC + TPA + SCAP (5%). The most frequent site of these lesions was the face (56%), followed by the scalp (13%). Lesions with the features of AGC were more frequently found on the face, especially the periocular region, than at other sites. TPA lesions were more frequent on the face and scalp than at other sites, whereas SCAP lesions were preferentially found on the face, scalp, and trunk. We also retrieved clinicopathological data and other information. We propose a unifying concept for AGC, TPA, and SCAP. Approximately one-third of these lesions are composite entities with the features of 2 or 3 different tumors, and we propose calling such tumors tubulopapillary cystic adenoma with apocrine differentiation.

Characteristics of Eccrine Tumors in a Tertiary Institution: A 5-Year Retrospective Study.

Eccrine tumors are adnexal tumors with a varied clinical presentation and wide histological spectrum. This study aims to consolidate data on the clinical characteristics of eccrine tumors to help improve clinical acumen and management of such tumors. Histopathological records from January 2008 to December 2012 were retrieved. Clinical characteristics of the tumor including site, appearance, symptoms, color, duration prior to presentation, and clinical and histological diagnosis were recorded. Eighty-four patients with eccrine tumors were identified, with seven main types of tumors recognized-hidradenoma (33.3%), poroma (29.8%), mixed tumors (14.3%), spiradenoma (8.3%), porocarcinoma (6.7%), eccrine adenoma (3.6%), and syringoma (3.6%). A total of 50% of mixed tumors were misdiagnosed as epidermal cysts. Eccrine tumors have a wide array of clinical presentations and are often clinically misdiagnosed as cysts. Recognizing certain clinical features may aid in the diagnosis, but, if in doubt, a biopsy should be performed.

[Apocrine poroma. A relatively little known skin tumor with multilineage differentiation]. / Das apokrine Porom. Ein wenig bekannter Hauttumor mit adnexieller Mischdifferenzierung.

Poromas were originally classified as eccrine tumors which predominantly consist of poroid ductal cells and differentiate in the direction of sweat gland ducts. However, there have now been many reports on poromas with additional differential characteristics differentiating in the direction of sebaceous and/or apocrine glands and/or hair follicles. These tumors have been termed apocrine poromas. Multilineage differentiation within a poroma can be explained by the embryological association of the sweat duct with the so-called folliculo-sebaceous-apocrine unit. The clinical and histopathological features of apocrine poromas are reviewed in comparison to classical eccrine poromas by taking into account seven own cases of apocrine poroma and a review of the literature. It is important for histopathologists not to confuse apocrine poroma with other tumors with multilineage differentiation. Apocrine poroma needs to be distinguished from sebaceoma and from basal cell carcinoma with sebaceous differentiation, in particular, because these tumors have therapeutic consequences for the patient. The main histopathological differences between apocrine poroma, sebaceoma and basal cell carcinoma with sebaceous differentiation are explained.

[Endocrine mucin-producing sweat gland carcinoma. three case reports with a brief review of the literature]. / Endokrines muzinproduzierendes Schweißdrüsenkarzinom. Drei Fallberichte mit kurzer Literaturübersicht.

Endocrine mucin-producing sweat gland carcinoma (EMPS) is a rare low-grade sweat gland carcinoma with an infiltrating growth pattern. It occurs mostly in women and shows a predilection for the periorbital region. Histopathologically, the tumor shows analogous features to endocrine ductal carcinoma/solid papillary carcinoma of the breast and shares some clinical and morphological similarities with primary mucinous carcinoma of the skin. The tumor is characterized by large monomorphous epithelial cells with little nuclear pleomorphism and only a few mitotic figures. The solid cystic tumor shows mucin-filled small cystic spaces, cribriform areas and expresses the neuroendocrine markers synaptophysin, chromogranin and neuron-specific enolase with varying staining intensities. The tumor cells are also positive for estrogen and progesterone receptors. We present three cases of this rare tumor with typical clinical, histopathological and immunohistochemical findings, give a short summary of the literature and discuss the most relevant differential diagnoses.

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.

A study of histopathologic spectrum of nodular hidradenoma.

BACKGROUND: Hidradenomas are rare benign adnexal neoplasms that encompass a morphological gamut with a range of differentiation. As a consequence, there is a great likelihood of being mistaken for other primary and metastatic tumors. Though conventionally regarded as eccrine, they have been reclassified into eccrine and apocrine types. OBJECTIVE: This study aims to document the histological spectrum of nodular hidradenomas, with particular reference to categorizing them into eccrine or apocrine tumors. RESULTS: A total of 15 cases with features of nodular hidradenoma with their age ranging from 18 years to 73 years were studied. Most of the cases were solitary, circumscribed, solid and cystic, dermal, symmetrical, lobulated tumors with a sheet-like and papillary architecture. The cells were chiefly eosinophilic with a regular oval grooved nucleus and a small inconspicuous nucleolus. Clear cells were also seen. Squamous differentiation was an important feature, with most showing a infundibular type of keratinization. Sebaceous differentiation is also common. The stroma varied from hyaline to myxoid. Only 1 case showed poroid differentiation. CONCLUSIONS: This study describes the assortment of histologic characteristics in hidradenomas. Apocrine hidradenomas are more common, contrary to earlier belief that favored an eccrine origin.

Immunohistochemical differentiation of four benign eccrine tumors.

BACKGROUND: The histogenesis and differentiation of eccrine tumors, including cylindroma, poroma, spiradenoma and syringoma, remains controversial. This controversy may be because of sporadic and incomplete studies of these neoplasms. METHODS: Ten examples each of normal eccrine structures and of four benign eccrine tumors are analyzed with antibodies to cytokeratin (CK) 7, CD34, CK6, CK10, smooth muscle actin (SMA) and CD10. These markers represent two different immunohistochemical stains for each part of the eccrine structure; CK7 and CD34 stain the secretory coil, CK6 and CK10 stain the straight duct and SMA and CD10 stain the myoepithelial cells. This redundancy in staining is performed on four benign eccrine tumors to better interpret the existing literature. RESULTS: We find that CK7 is a sensitive marker for the secretory coil; both cylindromas and spiradenomas express CK7. We also find that CK6 is a marker for the inner ductal cells, while CK10 is a marker for the middle ductal cells; syringomas express both these markers. SMA appears to be a more specific marker for myoepithelial cells surrounding normal eccrine coils, and none of the studied tumors express SMA or CD10. CONCLUSIONS: Our studies suggest that syringomas are tumors of the eccrine duct, while cylindromas and spiradenomas are tumors of the secretory coil.

Immunohistochemical Study of Non-Epithelial Cells in Spiradenoma.

BACKGROUND: Intratumoral lymphocytes are a defining feature of spiradenoma; however, there have only been a few reports on the phenotypic features of non-epithelial cells. Spiradenomas also contain numerous cells positive for S-100 protein and the nature of these cells is still controversial. METHODS: We performed a clinicopathological and immunohistochemical study of ten cases of spiradenoma. RESULTS: The study included seven men and three women. On histopathological examination, spiradenoma could be divided into two types: the vascular proliferating (VP) type (five cases) that featured granulation tissue with edema, vascular proliferation, and inflammatory cell infiltration into the stroma, and the common type (five cases), which did not include any of the aforementioned features. Immunohistochemical staining demonstrated a large number of cells positive for S-100 protein. These included cells with large pale nuclei, dendritic cells, and a few cells with small dark nuclei that were also positive for α-smooth muscle actin. Most of the cells infiltrating the parenchymata of these lesions were CD3-positive. The proportions of CD4-positive and CD8-positive cells were almost equal or CD8-positive cells were predominant. CD20+ cells were observed in five spiradenomas. In painful lesions, there were numerous nerve fibers near the tumor. CONCLUSIONS: In spiradenoma, CD3+ T cells were mainly seen in the parenchyma and CD8+ cells were predominant over CD4+ cells in most cases. CD20+ cells showed focal infiltration of the parenchyma and stroma, especially in VP-type lesions. S-100 protein-positive cells in spiradenoma contained not only Langerhans cells, but also cells with myoepithelial differentiation.

Apocrine lesions of the breast: part 1 of a two-part review: benign, atypical and in situ apocrine proliferations of the breast.

Apocrine morphology is a common phenomenon encountered in everyday breast pathology practice, and is defined as cuboidal or columnar cells exhibiting abundant eosinophilic granular cytoplasm, prominent apical granules, a low nuclear-cytoplasmic ratio, and round nuclei with pale chromatin and prominent nucleoli. Apocrine morphology is recognised in benign, atypical and malignant lesions of the breast. The morphology of apocrine atypia and non-high-grade apocrine ductal carcinoma in situ (DCIS) is less well defined due to the relative rarity of these lesions. In part 1 of this two-part review, we focus on the morphological characteristics of benign, atypical and in situ apocrine lesions of the breast, summarise the available data to date regarding distinction of atypical apocrine proliferations from non-high-grade apocrine DCIS and the biological significance of apocrine atypia, and provide practical guidance on handling these difficult lesions. Part 2 of this review will focus on the concept of pure apocrine carcinoma with emphasis on its definition and molecular data, including the current understanding of the molecular apocrine signature in breast carcinoma. We complete the review with a synopsis on the utility of immunohistochemistry in the diagnosis of apocrine lesions of the breast.

Head and neck sweat gland adenocarcinoma: A population-based perspective of a rare entity.

OBJECTIVES: Head and neck sweat gland adenocarcinoma (HNSGA) is an extremely rare malignancy. We present the first population-based analysis regarding this entity. STUDY DESIGN: Retrospective population-based analysis. METHODS: Using the Surveillance, Epidemiology, and End Results registry from 2000 to 2013, we extracted 627 cases of HNSGA. Data were analyzed for incidence trends, demographic and clinicopathologic traits, and predictors of disease-specific survival (DSS). RESULTS: The majority HNSGA cases were white, male, and 60 to 79 years old. The incidence was 0.036 per 100,000 people. Tumors most often presented as localized disease and histological grade II/III. The skin of the face was the most common primary site (43.4%), followed by the scalp and neck (31.6%). Overall 5-, 10-, and 20-year DSS were 94.6%, 89.6%, and 79.8%, respectively. Ethnicity did not affect survival, whereas a younger age at diagnosis and female sex conferred an advantage at 10 years (P = 0.0386) and 5 years (P = 0.0191), respectively. The origin of the HNSGA (apocrine vs. eccrine) did not affect outcomes. Regional and distant disease predicted worse DSS at 5, 10, and 20 years (P = 0.0026, P < 0.001, P < 0.001, respectively). Compared to grade I/II disease, grade III/IV dramatically worsened 5-, 10-, and 20-year DSS (P = 0.0035, P < 0.0001, P = 0.0011, respectively). Scalp and neck HNSGA exhibited the poorest 20-year DSS compared to other primary sites (P = 0.0024). CONCLUSION: We present the largest cohort of HNSGA. Significant poor prognostic indicators include older age, higher tumor grade, greater extent of invasion, and primary site of the scalp or neck. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2757-2762, 2017.

Aggressive digital papillary adenocarcinoma (aggressive digital papillary adenoma and adenocarcinoma revisited).

In 1987 a clinicopathologic study by the Armed Forces Institute of Pathology (AFIP) of rare sweat gland tumors, termed aggressive digital papillary adenoma and adenocarcinoma, was published. Since that time, the AFIP has continued to collect these tumors for study. Based on additional follow-up data, we think the original classification of these tumors requires revision. Sixty-seven cases of aggressive digital papillary adenoma and adenocarcinoma were studied according to their clinical characteristics and histologic features. Fifty of these were originally diagnosed as adenoma and 17 as adenocarcinoma. Follow up on 45 (67%) of the patients was obtained. None of the clinical or histologic parameters studied were found to be predictive of recurrence or metastasis, indicating that the originally proposed criteria for distinguishing between benign (adenoma) and malignant (adenocarcinoma) do not predict biologic behavior. When primary tumors were treated by subsequent reexcision or amputation, only one recurred (5%), when not so treated, 11 recurred (50%) regardless of the original diagnosis (p <0.05). Metastasis occurred in six (14%) cases and in three cases led to the death of the patient. Three of these metastatic cases had met the earlier criteria for adenoma. Pulmonary metastases were observed in five cases. No effective treatment for widespread metastatic disease has yet been developed. Because histologic features with prognostic significance could not be demonstrated in this retrospective review, we propose that all aggressive digital papillary tumors be designated aggressive digital papillary adenocarcinoma.

Syringoacanthoma. Acanthotic lesion of the acrosyringium.

An acanthotic and papillomatous cutaneous lesion with a seborrheic verruca (keratosis)-like clinical appearance that, under light microscope examination, shows intermingling of sweat ductal and epidermal cells is described. Other lesions related to the distal end of the eccrine sweat duct have been recorded before, but these lesions, named syringoacanthoma herein, have not been described previously, to my knowledge. Twenty-one cases of syringoacanthoma , 12 benign and nine malignant, are reviewed and their relationship with similar lesions is discussed.

Carcinoembryonic antigen in benign sweat gland tumors.

Carcinoembryonic antigen was demonstrated in sweat gland adenomas by immunostaining using standard immunoperoxidase techniques. Carcinoembryonic antigen could not be found in adnexal tumors derived from the pilar and sebaceous apparatus. The demonstration of this specific antigen in certain sweat gland tumors may be helpful in the recognition and classification of these kinds of lesions.

Carcinomas of sweat glands: report of 60 cases.

CONTEXT: Several aspects of sweat gland carcinomas (incidence, classification, diagnosis, and behavior) have not been definitively clarified and need to be studied further. OBJECTIVE: The clinicopathologic findings of a large series of sweat gland carcinomas, collected during a period of 15 years, are presented. METHODS: Sixty sweat gland carcinomas (41 porocarcinomas, 3 syringomatous carcinomas, 8 ductal carcinomas, 5 adenoid cystic carcinomas, and 3 mucinous carcinomas) were analyzed histologically and immunohistochemically. RESULTS: Porocarcinomas were composed of eosinophilic and clear atypical cells arranged in solid-cystic lobular masses. These tumors were divided into 2 subgroups: horizontal porocarcinomas, showing a prominent intraepidermal component, and nodular porocarcinomas, which demonstrated predominant nodular growth. Syringomatous carcinomas presented keratinizing and nonkeratinizing cysts, dilated tubules (sometimes with a "tadpole" appearance), small neoplastic ducts, solid islands, and cellular cords. Ductal carcinomas were characterized by a prominent formation of tubules, solid islands, and cellular cords. Adenoid cystic carcinomas presented a characteristic pattern, showing basaloid monomorphous cells with moderately atypical nuclei, arranged in cribriform or solid islands and in tubular structures. Mucinous carcinomas were composed of moderately atypical cells with eosinophilic vacuolated cytoplasm, forming solid and cystic islands floating in large mucin pools. Immunohistochemically, cytokeratin was found in neoplastic cells in all cases, carcinoembryonic antigen was detected in 73% of cases, and actin-positive (myoepithelial) cells were not found. CONCLUSIONS: Although numerous studies have been published in recent years, the histologic features, histogenesis, and classification of sweat gland carcinomas still remain controversial and need to be clarified by further studies.

Tumors of the epidermal appendages.

Benign tumors of the epidermal appendages frequently frustrate patient and doctor because of the uncertainty of the nature of the lesion and the choice that the benign lesion presents. Recognition and definitive management is usually straightforward with appropriate attention to the history and to the lesion. Knowledge of these benign epidermal appendage lesions can minimize time loss and expense and help to avoid unnecessary scars.

Sweat gland carcinoma: a clinicopathologic analysis of an expanded series in a single institution.

Primary adenocarcinoma of sweat glands is a rare tumor; approximately 220 cases have been reported in the last 30 years. We reviewed the charts of patients with primary diagnosis of this tumor treated at the Mayo Clinic between 1935 and 1995. We included only cases with initial histology slides available for re-examination. Tumors were classified into five recognizable histologic patterns (solid, ductal, mucinous, microcystic adnexal, and adenocystic carcinoma) and graded by the Broder system. Statistical analysis consisted of Kaplan-Meier product limit method and Cox multiple regression test. In total, 55 patients were identified, and age ranged from 13 to 85 years (mean 59 years). Thirty-six patients (65 percent) presented to the Mayo Clinic for initial treatment; all except one had disease limited to the primary site. Microcystic adnexal carcinoma was the most frequent type, and more than 50 percent were grade 2 tumors. Among these 36 patients, 4 had some type of recurrence. Patients who developed metastasis had a high-grade tumor in the initial biopsy. Nineteen patients were referred with recurrence; 13 had local recurrence, 4 had regional diseases, and 2 had distant metastases. The histologic distribution showed 47 percent solid tumors, and 37 percent of them were grade 3. Multiple regression analysis did not show a difference in recurrence or survival when gender, age, tumor location, or histologic pattern was evaluated. In addition, there was no difference in the outcome between wide surgical resection and micrographic surgery. The only predictive factor for distant metastases and/or death (p < 0.003) was histologic grade. Overall 10-year survival rate was 86 and 60 percent for primary and referred patients, respectively. We conclude that histologic diagnosis of sweat gland carcinoma must be complemented by clinical examination to evaluate metastases. Clinical behavior depends on the histologic type of tumor, degree of differentiation, and clinical stage. On recurrence, the likelihood of further recurrences and mortality increases dramatically. Aggressive initial local ablation with tumor-free margins is recommended. In high-grade tumors, prophylactic regional lymph node dissection may further characterize tumor aggressiveness and may justify adjuvant radiotherapy as part of the primary treatment.

Malignant eccrine tumor--a case report and a classification of tumors of eccrine sweat apparatus.

A case of malignant eccrine tumor and its histological findings were reported. In this case, we considered basal cell carcinoma or malignant melanoma clinically; however, the histological features matched those of malignant eccrine tumor. It has been said that it is very difficult to determine the origin of tumors of sweat apparatus; to contribute to this ongoing dialogue, the classification of tumors of eccrine sweat apparatus was also discussed.