Based on Immune Microenvironment and Genomic Status, Exploring Immunotherapy in Advanced Hidradenocarcinoma: A Retrospective Analysis.

There are no standard treatment guidelines for hidradenocarcinoma, and the immune microenvironment and genomic data are very limited. Thus, in this study the immune microenvironment and genomic indicators in hidradenocarcinoma was investigated, and immunotherapy for hidradenocarcinoma was initially explored. Forty-seven hidradenocarcinoma patients were retrospectively collected. Immunohistochemical staining was performed to identify CD3/CD8+ T cells and programmed death ligand-1 expression. In total, 89.4% and 10.6% of samples had Immunoscores of 0-25% and 25-70%. Tumour proportion score distribution was as follows: tumour proportion score < 1% in 72.4%, 1-5% in 17.0%, and > 5% in 10.6%. Combined positive score distribution was as follows: combined positive score < 1 in 63.8%, 1-5 in 14.9%, and > 5 in 21.3%. Next-generation sequencing revealed that TP53 (33%), PI3KCA (22%), and ERBB3 (22%) were the most frequently mutated genes. The PI3K-Akt signalling pathway, growth, and MAPK signalling pathways were significantly enriched. Five patients had a low TMB (< 10 muts/Mb), and 9 patients had MSS. Three patients treated with immune combined with chemotherapy achieved significant tumour regression, and the progression-free survival was 28.8 months. In conclusion, the hidradenocarcinoma immune microenvironment tends to be noninflammatory. Evidence-based targets for targeted therapy are lacking. Immunotherapy combined with chemotherapy may be better for most advanced hidradenocarcinoma patients with a noninflammatory microenvironment.

Bilateral Eyelid Polyposis Due to Eccrine Hidrocystoma.

This case report discusses a diagnosis of eccrine hidrocystoma in a female patient aged 65 years who presented with bilateral, painless eyelid masses.

Case of eccrine chondroid syringoma of the upper lip.

Chondroid syringoma (CS) is a benign, slow-growing mixed tumour that arises from the sweat glands and usually presents in the head and neck area. Histopathological examination is important for proper diagnosis, as CS is often confused with epidermal cysts due to its rare presentation. This article presents a man in his 40s with a right upper lip mass that emerged 6 months prior to presentation. An intraoral surgical excision was performed and the histopathological analysis revealed solid epithelial cells that formed multiple, non-branching ducts lined by cuboidal epithelium. Cystic spaces were filled by heterogeneous eosinophilic material embedded in chondromyxoid stroma. Histopathology identified the lesion as an eccrine-variant CS. The patient recovered well.

Primary cutaneous apocrine carcinoma with RARA::NPEPPS fusion.

Gene fusions have emerged as crucial molecular drivers of oncogenesis in a subset of cutaneous adnexal neoplasms, including poroid neoplasms and hidradenomas. We present a unique case of primary cutaneous apocrine carcinoma harboring RARA::NPEPPS fusion, broadening the spectrum of fusion-associated cutaneous adnexal neoplasms. A 77-year-old African American male presented with an ulcerated thigh nodule. Histopathologically, the predominantly dermal-based adenocarcinoma exhibited papillary, micropapillary, cribriform, and solid growth patterns with central comedonecrosis, set in a fibrotic/desmoplastic stroma. Immunophenotypically, the neoplastic cells were positive for CK7, CK19, GATA3, TRPS1, HER2, CK5/6, calretinin, p63, and DPC4 (no loss), while lacking immunoreactivity for CK20, CDX2, TTF1, napsin-A, PAX8, arginase-1, adipophilin, NKX3.1, uroplakin II, and D2-40. The immunoprofile and clinical and radiographic absence of any internal malignancy, including breast carcinoma, except for multiple lymphadenopathy, supported the diagnosis of primary cutaneous apocrine carcinoma. Next-generation sequencing unveiled the novel RARA::NPEPPS fusion, concurrent ERBB2 amplification, and multiple somatic mutations involving TP53, CDKN2A, BRCA2, PIK3CA, PIK3R1, and others. The patient developed widespread metastases within a year after the initial diagnosis, indicating the tumor's aggressive behavior. This novel fusion, unprecedented in any human malignancies including primary cutaneous adnexal carcinomas, may suggest a potential new subtype within primary cutaneous adnexal carcinoma.

Epidemiology and classification for canine and feline mammary gland tumors: a histopathological survey of 437 mammary gland tumor biopsies performed in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019.

Background: Metastatic disease resulting from mammary gland tumors (MGTs) is a known cause of death among dogs and cats. Keys to successful prevention and management strategies involve the accurate recording of diagnostic data. Methods: This retrospective study reviewed the epidemiology and classification of canine mammary gland tumors (CMTs) and feline mammary gland tumors (FMTs), as well as the factors including sex, age, and breed related to the occurrence of these tumors. Accordingly, 1,736 tumor biopsy cases were reported from 2012 to 2019 at Chiang Mai University Small Animal Hospital, Thailand, with 1,639 canine tumor biopsy cases and 97 feline tumor biopsy cases. Results: The proportion of CMTs was reported at 24.5% (401/1,639) for all canine tumor biopsy cases. Benign and malignant tumors were reported at 14.5% (58/401) and 85.5% (343/401) for all CMT cases, respectively. The mean age of dogs affected by benign CMTs was 9.0 ± 3.0 years, which was significantly lower than for malignant CMTs at 9.9 ± 2.8 years (P = 0.0239). According to histopathological classification, benign mixed tumors and simple carcinoma types were highest among benign and malignant CMT cases, respectively. Moreover, female dogs were at significantly higher risk of developing mammary gland tumors (OR = 45.8, 95% CI [3.9-86.0], P < 0.0001) than male dogs, as well as older dogs (>8 years) (OR = 1.7, 95% CI [1.2-2.2], P = 0.0001) compared to young ones (≤8 years). The proportion of FMTs was 37.1% (36/97) for all feline tumor biopsy cases. Benign and malignant tumors for all FMTs were reported at 16.7% (6/36) and 83.3% (30/36), respectively. According to histopathological classifications, adenoma and simple carcinoma were present in the highest proportion among benign and malignant FMTs, respectively. Female cats were at a significantly higher risk of developing mammary gland tumors than male cats (OR = 25.7, 95% CI [3.9-272.8], P < 0.0001). Conclusions and clinical importance: There was a high proportion of MGT cases compared with other tumor cases reported in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019, and malignant tumor biopsies have been more frequently observed than benign tumor biopsies in both CMT and FMT cases. The resulting data originating from this study can be an aid for veterinary oncologists in better educating clients and planning treatment and prevention strategies and it can be used as a basis for further experimental studies in the oncology section.

Epidermodysplasia verruciformis-associated eccrine neoplasm: a rare entity with distinctive clinical and histopathologic features.

Most tumors are caused by inherited or acquired genetic changes. However, a subset of tumors is driven by viral infection including Kaposi sarcoma, nasopharyngeal carcinoma, and others. Human papillomavirus (HPV) is an especially common cause of epithelial cancers and hyperplasias. Epidermodysplasia verruciformis (EDV) is a rare type of HPV infection with characteristic histopathologic features and a unique spectrum of HPV subtypes. We report here a distinctive form of EDV-associated eccrine neoplasia. Seven tumors from two patients were analyzed and show highly uniform features including multiple clustered clinical lesions, multifocal epidermal origin, eccrine differentiation with close association with the acrosyringium, an anastomosing growth pattern, and a bland monotonous poroid-to-basaloid cytomorphology. Clinical follow-up for one patient has been benign to date. These tumors show strong similarity to two previously reported cases, suggesting that this type of EDV-associated eccrine neoplasia may represent a rare but reproducible form of skin adnexal tumor with distinctive clinicopathologic features.

Challenging diagnosis of male intraductal papilloma masquerading as eccrine hidradenoma in the breast: Case report.

RATIONALE: This article presents a challenging case involving an elderly male patient with a misdiagnosed intraductal mammary papilloma initially identified as a sweat adenoma through ultrasound imaging. The study aims to explore the histopathology, clinical presentations, and sonographic features of both conditions, emphasizing the contributing factors to the diagnostic misstep. PATIENT CONCERNS: A 61-year-old male reported a persistent left breast mass, along with pain and swelling, spanning a 6-month duration. DIAGNOSES: Ultrasound examination indicated a deep, square, mixed-echo mass in the left nipple, initially suggestive of a sweat adenoma. However, subsequent pathological analysis following resection under general anesthesia confirmed an intraductal papilloma. INTERVENTION: The patient underwent surgical resection of the left breast mass under general anesthesia. OUTCOME: Post-surgery, the patient exhibited satisfactory recovery; however, regrettably, he was lost to follow-up. LESSONS: This study underscores the challenge in differentiating between clear cell sweat adenoma and male intraductal mammary papilloma solely based on ultrasonic characteristics. It emphasizes the susceptibility of ultrasound-based diagnoses to misinterpretation, highlighting the critical need for a comprehensive pathological examination to establish a definitive diagnosis.

Recurrent GATA3 P409Afs*99 Frameshift Extension Mutations in Sweat-gland Carcinoma With Neuroendocrine Differentiation.

Sweat-gland carcinoma with neuroendocrine differentiation (SCAND) was recently proposed as a new cutaneous adnexal neoplasm with neuroendocrine differentiation; however, its genetics are not well known. Herein, we performed clinicopathologic and genetic analyses of 13 SCAND cases and 5 control cases of endocrine mucin-producing sweat gland carcinoma (EMPSGC). The SCAND group included 11 males and 2 females with a median age of 68 years (range, 50 to 80 y). All SCAND lesions occurred in the ventral trunk or genital area. Of the 13 SCAND cases, 9 and 5 exhibited lymph node and distant metastases, respectively. Three (23.1%) patients with SCAND died of the disease. In contrast, neither metastasis nor mortality was confirmed in the EMPSGC cases. Immunoexpression of the androgen receptor, c-Myb, and MUC2 was limited in SCAND, whereas EMPSGC frequently expressed these immunomarkers. GATA3 P409Afs*99 extension mutations were detected in 7 (53.8%) of the 13 SCAND cases, using Sanger or panel sequencing. All 7 SCAND cases with GATA3 mutations were located in the genital, inguinal, or lower abdominal regions, whereas 5 of the other 6 SCAND cases were located in the anterior upper to mid-trunk. No GATA3 mutations were detected in the EMPSGC cases (0/5, 0%). These clinicopathologic and genetic findings support SCAND as a tumor entity distinguishable from EMPSGC. In addition, the characteristic frameshift extension mutations in GATA3 contribute to the establishment of the tumor-type concept of SCAND.

Cutaneous Malignant Mixed Tumor With Pulmonary Metastasis: A Case Report and Literature Review.

BACKGROUND: Cutaneous malignant mixed tumor (MMT) is a rare sweat gland-derived tumor characterized by admixed malignant epithelial cells and chondromyxoid stroma. Approximately 50 cases have been described in the literature. Metastasis, which may occur in more than one-third of cases, is most common in the lung. METHODS: We summarized the clinicopathologic features of a patient with cutaneous MMT metastatic to the lungs. A literature review of similar cases was completed using Web of Science, Scopus, and PubMed databases. RESULTS: A woman in her 70s presented with an enlarging mass on her left eyebrow; histopathologic examination showed large islands of atypical cells with increased mitotic activity, admixed with necrosis on a background of fibrotic and chondromyxoid stroma. Multiple lung nodules were identified during follow-up. Examination of a pulmonary core needle biopsy specimen was consistent with metastatic cutaneous MMT. Literature review identified 10 cases published between 1980 and 2017. Most primary tumors were large (≥4 cm). Local recurrence was uncommon, and the lung was the only metastatic site in 5 cases. Histopathologically, metastatic tumors were described as more cellular, with diminished stromal tissue compared with the primary lesion. CONCLUSION: This is 1 of the 11 reports of cutaneous MMT with metastasis to the lungs found in the English-language literature published after 1980. Of note, most reports were published before 1990, making this case study one of the few contemporary descriptions of cutaneous MMT with pulmonary metastases. We think that the present case report will increase the awareness of this rare tumor.

Five-year pattern of adnexal tumors of the skin in Ethiopia.

BACKGROUND: Adnexal tumors of the skin are rare neoplasms that encompass a wide range of dermatologic entities. Here, we investigated the pattern of adnexal tumors of the skin in the All African Leprosy and Tuberculosis Rehabilitation and Training Center (ALERT) hospital retrospectively. METHODS: A hospital-based retrospective study was conducted at ALERT from histopathology records in the Armauer Hansen Research Institute (AHRI) pathology laboratory of patients diagnosed with any of the skin adnexal tumors during the time period January 2017 to December 2021. A structured data extraction sheet was used. Data entry was done using EpiData 4.6.0.6. Data were analyzed using SPSS version 25. RESULT: A total of 146 skin adnexal tumors were identified making the magnitude 2.8% of total biopsies. The 3rd decade of life was found to be the most common age group. Male-to-female ratio was 1 : 1.05. Majority of the tumors were benign (82.2%) and had sweat gland differentiation at 48.6%. Poroma (10.9%) was the most frequent tumor, whereas porocarcinoma (6.8%) made up the most frequent malignant tumor. The most common site was the head and neck region (48.6%). Only 21.2% of the tumors were correctly identified clinically. CONCLUSION: The magnitude of skin adnexal tumors is found to be slightly higher than other similar studies which could be because it was carried out in the largest dermatologic center in the country. The most common skin adnexal tumors identified, their localizations, and lines of differentiation are all in line with other studies. Histopathologic examination is mandatory for the accurate diagnosis of these tumors.

SOX10-Internal Tandem Duplications and PLAG1 or HMGA2 Fusions Segregate Eccrine-Type and Apocrine-Type Cutaneous Mixed Tumors.

Cutaneous mixed tumors exhibit a wide morphologic diversity and are currently classified into apocrine and eccrine types based on their morphologic differentiation. Some cases of apocrine-type cutaneous mixed tumors (ACMT), namely, hyaline cell-rich apocrine cutaneous mixed tumors (HCR-ACMT) show a prominent or exclusive plasmacytoid myoepithelial component. Although recurrent fusions of PLAG1 have been observed in ACMT, the oncogenic driver of eccrine-type cutaneous mixed tumors (ECMT) is still unknown. The aim of the study was to provide a comprehensive morphologic, immunohistochemical, and molecular characterization of these tumors. Forty-one cases were included in this study: 28 cases of ACMT/HCR-ACMT and 13 cases of ECMT. After morphologic and immunohistochemical characterization, all specimens were analyzed by RNA sequencing. By immunohistochemistry, all cases showed expression of SOX10, but only ACMT/HCR-ACMT showed expression of PLAG1 and HMGA2. RNA sequencing confirmed the presence of recurrent fusion of PLAG1 or HMGA2 in all cases of ACMT/HCR-ACMT, with a perfect correlation with PLAG1/HMGA2 immunohistochemical status, and revealed internal tandem duplications of SOX10 (SOX10-ITD) in all cases of ECMT. Although TRPS1::PLAG1 was the most frequent fusion, HMGA2::WIF1 and HMGA2::NFIB were detected in ACMT cases. Clustering analysis based on gene expression profiling of 110 tumors, including numerous histotypes, showed that ECMT formed a distinct group compared with all other tumors. ACMT, HCR-ACMT, and salivary gland pleomorphic adenoma clustered together, whereas myoepithelioma with fusions of EWSR1, FUS, PBX1, PBX3, POU5F1, and KLF17 formed another cluster. Follow-up showed no evidence of disease in 23 cases across all 3 tumor types. In conclusion, our study demonstrated for the first time SOX10-ITD in ECMT and HMGA2 fusions in ACMT and further refined the prevalence of PLAG1 fusions in ACMT. Clustering analyses revealed the transcriptomic distance between these different tumors, especially in the heterogenous group of myoepitheliomas.

Nectin-4 expression in a subset of cutaneous adnexal carcinomas: A potential target for therapy with enfortumab vedotin.

BACKGROUND: Enfortumab vedotin (EV) is an antibody-drug conjugate directed against Nectin-4 that is used to treat urothelial carcinoma. Nectin-4 is inherently expressed in the skin and adnexal structures. Since therapeutic options for cutaneous adnexal carcinomas are limited, we sought to evaluate Nectin-4 expression in adnexal carcinomas and benign adnexal neoplasms to identify tumors that are potentially targetable with EV. METHODS: Eight sebaceous carcinomas (seven periocular and one lymph node metastasis), eight digital papillary adenocarcinomas, seven squamoid eccrine ductal carcinomas, eight poromas, eight trichilemmomas, and seven sebaceous adenomas were subjected to immunohistochemical staining for anti-Nectin-4 antibody. H-scores for Nectin-4 expression were calculated. RESULTS: Benign adnexal neoplasms had a significantly lower mean (±SD) Nectin-4 H-score (142.6 ± 39.1) than did the adnexal carcinomas (198 ± 90.8; p = 0.006). Nectin-4 was expressed in 91% (21/23) of adnexal carcinomas. Sebaceous carcinomas frequently exhibited high expression of Nectin-4 (88% [7/8]), with a mean (±SD) H-score (258.1 ± 58.4) significantly higher than those for digital papillary adenocarcinomas (197.5 ± 52.5; p = 0.035) and squamoid eccrine ductal carcinomas (131.4 ± 114.1; p = 0.031). Sebaceous carcinomas also had significantly higher H-scores than did sebaceous adenomas (186.4 ± 25.0; p = 0.013). CONCLUSIONS: Increased Nectin-4 expression in a subset of cutaneous adnexal carcinomas, particularly sebaceous carcinomas, reveals that EV is a potential therapeutic option for these tumors.

Significantly Higher 68 Ga-FAPI Than 18 F-FDG Uptake by Hidradenocarcinoma of Head and Neck on PET/CT.

ABSTRACT: Hidradenocarcinoma is quite rare in clinical practice. Herein, we describe the 68 Ga-FAPI and 18 F-FDG PET/CT findings of hidradenocarcinoma of the head and neck in a 75-year-old man. In the present case, the primary tumor and secondary lesions showed intense accumulation of 68 Ga-FAPI but only slight 18 F-FDG uptake. This case demonstrates that 68 Ga-FAPI PET/CT might be used as a helpful tool for evaluating hidradenocarcinoma.

Molecular Profiling of Syringocystadenocarcinoma Papilliferum Reveals RAS-Activating Mutations.

CONTEXT.­: Syringocystadenocarcinoma papilliferum (SCACP) is a rare adnexal carcinoma and the malignant counterpart of syringocystadenoma papilliferum (SCAP), which is commonly located on the head and neck and may arise in association with a nevus sebaceus. RAS mutations have been identified in both SCAP and nevus sebaceus. OBJECTIVE.­: To evaluate the clinicopathologic and molecular features of SCACPs, which have not been previously explored. DESIGN.­: We obtained 11 SCACPs from 6 institutions and reviewed the clinicopathologic features. We also performed molecular profiling using next-generation sequencing. RESULTS.­: The cohort comprised 6 women and 5 men with ages ranging from 29 to 96 years (mean, 73.6 years). The neoplasms occurred on the head and neck (n = 8; 73%) and extremities (n = 3; 27%). Three tumors possibly arose in a nevus sebaceus. A total of 4 cases showed at least carcinoma in situ (adenocarcinoma, n = 3; squamous cell carcinoma [SCC], n = 1), and 7 cases were invasive (SCC, n = 5; mixed adenocarcinoma + SCC, n = 2). A total of 8 of 11 cases (73%) had hot spot mutations consisting of HRAS (n = 4), KRAS (n = 1), BRAF (n = 1), TP53 (n = 4), ATM (n = 2), FLT3 (n = 1), CDKN2A (n = 1), and PTEN (n = 1). All 4 cases with HRAS mutations occurred on the head and neck, whereas the KRAS mutation occurred on the extremity. CONCLUSIONS.­: RAS-activating mutations were detected in 50% of the cases, of which most (80%) involved HRAS and occurred on the head and neck, which shows overlapping features with SCAP, supporting that a subset may arise as a result of malignant transformation and likely an early oncogenic event.

Spindle cell porocarcinoma with a novel YAP1::MAML3 fusion.

Porocarcinomas are rare sweat gland cancers representing the malignant counterpart to benign poromas. Their diagnosis can be challenging, especially in the absence of an associated poroma or when the tumor is poorly differentiated. Since recurrent YAP1::MAML2 and YAP1::NUTM1 fusions have been identified in poroid tumors, molecular studies provide an opportunity to support the diagnosis in challenging cases. We describe a case of a female patient in her early 90s, with a polypoid mass of the hip. Histopathologically, there was a poorly differentiated malignant spindle cell tumor adjacent to a poroma. Because of the close association with a poroma and immunoreactivity for p40, a diagnosis of spindle cell porocarcinoma was rendered, which was further supported by YAP1 immunohistochemical studies. Antibodies targeting both the N-terminus and C-terminus confirmed YAP1 rearrangement in both the poroma and the spindle cell neoplasm. Subsequent targeted RNA sequencing revealed a YAP1::MAML3 gene fusion. MAML3 has previously not yet been reported as a YAP1 fusion partner in porocarcinoma. With the illustration of a rare spindle cell variant of porocarcinoma and the identification of a novel gene fusion, this case report expands the spectrum of morphologic and genomic aberrations associated with porocarcinoma.