Sweat Gland Tumors Research Articles

Pigmented Syringomatous Carcinoma/Sweat Gland Carcinoma of the Vulva With Melanocytic Colonization: An Uncommon Presentation of a Rare Sweat Gland Neoplasm

Abstract: Primary vulvar carcinomas are rare and constitute a diverse group of neoplasms. These primary tumors are typically classified based on their presumed tissue of origin or histological characteristics. Among these, carcinomas of sweat gland origin are particularly significant. They closely resemble similar malignancies in nonvulvar skin, including various cutaneous adnexal-type cancers such as apocrine and eccrine adenocarcinomas. Syringomatous carcinoma of the vulva is a rare malignant sweat gland neoplasm known for its infiltrative growth and tendency for local recurrence. Typically, these malignancies manifest as nonulcerated nodules or plaques, primarily in the head and neck region. The occurrence of syringomatous carcinoma in the vulvar region is exceptionally rare. Herein, we present a unique case of a 35-year-old woman with a dark mole measuring 1.5 × 1.0 cm on the vulva. Complete excision was performed to exhibit an infiltrative haphazard proliferation of elongated ductules and tubules, displaying significant cytologic atypia characterized by irregular nuclear contours and variably prominent nucleoli. Extensive melanocytic pigment deposition and stromal fibrosis were also observed. Immunohistochemical staining demonstrated positive expression of epithelial markers, including keratins (AE1/AE3) and epithelial membrane antigen, supporting the diagnosis of syringomatous carcinoma. CK7 and carcinoembryonic antigen were negative, whereas SOX10 and pan melanin highlighted admixed, cytologically bland melanocytes within the epidermis and neoplastic nests. This case represents a highly unusual presentation of syringomatous carcinoma associated with melanocyte colonization. Due to limited data on the optimal management strategies, a multidisciplinary approach involving gynecologic oncologists, dermatopathologists, and radiation oncologists is essential for treatment decisions. Long-term follow-up is crucial, considering the potential for local recurrence and metastatic spread, emphasizing the importance of comprehensive clinical management for favorable patient outcomes of this rare malignancy.

Squamoid Eccrine Ductal Carcinoma Displays Ultraviolet Mutations and Intermediate Gene Expression Relative to Squamous Cell Carcinoma, Microcystic Adnexal Carcinoma, and Porocarcinoma

Squamoid eccrine ductal carcinoma is a rare infiltrative tumor with morphologic features intermediate between squamous cell carcinoma (SCC) and sweat gland carcinomas such as microcystic adnexal carcinoma. Although currently classified as a sweat gland carcinoma, it has been debated whether squamoid eccrine ductal carcinoma is better classified as a variant of SCC. Furthermore, therapeutic options for patients with advanced disease are lacking. Here, we describe clinicopathologic features of a cohort of 15 squamoid eccrine ductal carcinomas from 14 unique patients, with next-generation sequencing DNA profiling for 12 cases. UV signature mutations were the dominant signature in the majority of cases. TP53 mutations were the most highly recurrent specific gene alteration, followed by mutations in NOTCH genes. Recurrent mutations in driver oncogenes were not identified. By unsupervised comparison of global transcriptome profiles in squamoid eccrine ductal carcinoma (n = 7) to SCC (n = 10), porocarcinoma (n = 4), and microcystic adnexal carcinoma (n = 4), squamoid eccrine ductal carcinomas displayed an intermediate phenotype between SCC and sweat gland tumors. Squamoid eccrine ductal carcinoma displayed significantly higher expression of 364 genes (including certain eccrine markers) and significantly lower expression of 525 genes compared with other groups. Our findings support the classification of squamoid eccrine ductal carcinoma as a carcinoma with intermediate features between SCC and sweat gland carcinoma.

Sweat gland tumor: A rare diagnosis of eyelid mass- A case report

Eccrine acrospiroma or Nodular hidradenomas are extremely rare sweat gland tumors of eyelid that arise as intradermal nodules from eccrine sweat glands. This case reports documents evaluation of a nodular mass of upper eyelid and its adequate management. Clinical examination followed by wide local excision and histopathologic evaluation of mass was done. Clinically, the mass was diagnosed as sebaceous cell carcinoma of eyelid. Post-operative histopathologic evaluation of the mass was suggestive of benign acrospiroma. Sweat gland tumors constitute of a very small proportion of eyelid tumors which often mimic other malignant tumors of eyelid.

A rare tumour – metastatic digital papillary adenocarcinoma: literature review, clinical case of successful therapy

Digital papillary adenocarcinoma (DPA ) is a rare malignant neoplasm of sweat glands, which was first described by Helwig in 1979 and then classified by Kao in 1987. This disease most often occurs in men aged 50–70 years and is characterized by a relatively favorable prognosis. In most cases, radical excision of the tumor leads to cure. However, 14–47 % of patients develop distant metastases with predominant lung involvement (70 %). The study of etiology and pathogenesis of this rare cancer and its molecular genetic profile seems to be interesting. Currently, there is no clear approach to the treatment of metastatic DPA , but sporadic cases of using chemotherapy have been reported. Aim of the study: to analyze current data on the pathogenesis of DPA , diagnostic features and treatment methods used, as well as to present the first clinical case of treatment of disseminated digital carcinoma with immune checkpoint inhibitors described in scientific literature. Material and Methods. A search of available literature published in Medline, Pubmed, etc. databases from 1984 to 2023 was performed, 21 sources were included in this review. Clinical Case Description. We present a rare case of metastatic digital papillary carcinoma in a 23-year-old male with disease manifestation at the age of 14 years. Lack of vigilance and awareness of oncologists and morphologists did not allow timely diagnosis of malignancy, even in case of 3 local recurrences of the disease. Only biopsy of a metastatic lung nodule with histological and IHC examination (of archival and new material) made it possible to make a correct diagnosis. This case revealed 2 potential targets that could be used for disease control: androgen receptor positive expression and PD -L1 expression with CPS =20. The use of immune response checkpoint inhibitors (ipilimumab + nivolumab) resulted in partial response followed by stable disease.

Gene expression profiling in porocarcinoma indicates heterogeneous tumor development and substantiates poromas as precursor lesions.

Malignant sweat gland tumors are rare, with the most common being eccrine porocarcinoma (EP). Approximately 18% of benign eccrine poroma (EPO) transit to EP. Previous research has provided first insights into the mutational landscape of EP. However, only few studies have performed gene expression analyses. This leaves a gap in the understanding of EP biology and potential drivers of malignant transformation from EPO to EP. Transcriptome profiling of 23 samples of primary EP and normal skin (NS). Findings from the EP samples were then tested in 17 samples of EPO. Transcriptome profiling revealed diversity in gene expression and indicated biologically heterogeneous sub-entities as well as widespread gene downregulation in EP. Downregulated genes included CD74, NDGR1, SRRM2, CDC42, ANXA2, KFL9 and NOP53. Expression levels of CD74, NDGR1, SRRM2, ANXA2, and NOP53 showed a stepwise-reduction in expression from NS via EPO to EP, thus supporting the hypothesis that EPO represents a transitional state in EP development. We demonstrated that EP is molecularly complex and that evolutionary trajectories correspond to tumor initiation and progression. Our results provide further evidence implicating the p53 axis and the EGFR pathway. Larger samples are warranted to confirm our findings.

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.

Porocarcinomas with PAK1/2/3 fusions: a series of 12 cases.

Porocarcinoma is a malignant sweat gland tumour differentiated toward the upper part of the sweat duct and may arise from the transformation of a preexisting benign poroma. In 2019, Sekine etal. demonstrated the presence of YAP1::MAML2 and YAP1::NUTM1 fusions in most poromas and porocarcinomas. Recently, our group identified PAK2-fusions in a subset of benign poromas. Herein we report a series of 12 porocarcinoma cases harbouring PAK1/2/3 fusions. Five patients were male and the median age was 79 years (ranges: 59-95). Tumours were located on the trunk (n = 7), on the thigh (n = 3), neck (n = 1), or groin area (n = 1). Four patients developed distant metastases. Microscopically, seven cases harboured a benign poroma component and a malignant invasive part. Ductal formations were observed in all, while infundibular/horn cysts and cells with vacuolated cytoplasm were detected in seven and six tumours, respectively. In three cases, the invasive component consisted of a proliferation of elongated cells, some of which formed pseudovascular spaces, whereas the others harboured a predominant solid or trabecular growth pattern. Immunohistochemical staining for CEA and EMA confirmed the presence of ducts. Focal androgen receptor expression was detected in three specimens. Whole RNA sequencing evidenced LAMTOR1::PAK1 (n = 2), ZDHHC5::PAK1 (n = 2), DLG1::PAK2, CTDSP1::PAK1, CTNND1::PAK1, SSR1::PAK3, CTNNA1::PAK2, RNF13::PAK2, ROBO1::PAK2, and CD47::PAK2. Activating mutation of HRAS (G13V, n = 3, G13R, n = 1, Q61L, n = 2) was present in six cases. Our study suggests that PAK1/2/3 fusions is the oncogenic driver of a subset of porocarcinomas lacking YAP1 rearrangement.

MALIGNANT SWEAT GLAND TUMOURS: A CASE SERIES

Objectives: Malignant sweat gland tumor is a very rare skin cancer with variable presentations. The objectives of this study are to examine the clinicopathological and immunohistochemical features of malignant sweat gland tumors and to discuss the treatment and follow-up for postsurgical recurrence rates. Methods: Six patients diagnosed with sweat gland carcinoma at the National Hospital of Dermatology and Venereology between 2018 and 2023 were carefully reviewed. Results: The cases occurred in four men and two women, ranging in age from 31 to 78 years (mean 59.3). Four of the lesions were from the scalp, one from the nose, and one from the right arm. There were three cases of Eccrine Porocarcinoma, two cases of Hidradenocarcinoma, and one case of Syringoid Eccrine Carcinoma. All of them were treated with surgery, five cases with wide local excision, and one case with Mohs micrographic surgery. Only one case had a recurrence. Conclusion: Malignant sweat gland tumors demonstrate significant variability in clinicopathology and immunohistopathology. Surgery is the mainstay of treatment. Received 28 June 2023Revised 26 September 2023Accepted 29 November 2023

Apocrine Hidrocystoma- A Histological Diagnosis

An Asian female in her 20s, presented with a painless swelling in the left upper eyelid for 2 years. A cystic, non-tender, well defined swelling of 3 by 4 mm with a punctum was seen in the medial aspect of left upper eyelid. Best corrected visual acuity was 20/20 in both eyes, with anterior and posterior segment examination within normal limits in both eyes. Provisional diagnosis of Sebaceous cyst was made, excision of cyst was planned for cosmetic indication. Cyst removal in toto was done and sent for histopathological examination. HPE report was awaited and came the surprise report - APOCRINE HIDROCYSTOMA, a rare, benign, cystic tumor of the apocrine sweat glands. Since surgical excision is the treatment option for apocrine hidrocystoma, patient was informed of the same and reassured. The diagnosis is histological and hence apocrine hidrocystoma must be kept in mind while considering differential diagnosis of cystic lesions in ocular adnexa.

Comparing Porocarcinoma Outcomes Following Resection by Surgical Management Technique

Introduction Porocarcinoma is a neoplasm of eccrine sweat glands. While wide local excision (WLE) has traditionally been the surgical technique of choice for porocarcinoma resection, the number of cases treated using Mohs micrographic surgery (MMS) is increasing. Methods We performed a retrospective review of patients diagnosed with porocarcinoma from January 2015 - February 2020. Chi-square and Fisher’s exact test was used to evaluate outcomes. Results Twelve patients were evaluated following surgical treatment. WLE recipients were younger, with an equal number of white and black patients. All MMS patients were white (4). Both WLE and MMS were most performed on the head and neck (6 and 3, respectively). Local recurrence rate was 12.5% in the WLE group (vs. 0% for MMS). Mortality rate was 25% for each group. Discussion Prognosis following WLE is poor. Our results suggest that MMS is a useful modality for the surgical treatment of porocarcinoma.

Clear Cell Hidradenoma with Extensive Mucinous Change in the Axillary Tail of Breast as Mimicker: A Rare Case Report

Introduction: Clear cell hidradenoma (CCH) is a rare benign tumor of sweat gland. It can mimic other diseases clinically, radiologically and histologically when found in axilla. Methods: A 62-year-old female presented with a solitary lump in the axillary tail of her breast. Differentials in clinical examination and imaging were breast neoplasm and lymph nodal mass. Results: The patient underwent preoperative diagnostic workup, and the lesion was suspicious of hidradenoma. She underwent wide excision of the lesion. The final histopathological examination was suggestive of CCH with extensive mucinous change. Conclusion: Even though rare, hidradenoma should always be kept as a differential when presented as a solitary painless swelling. The present case represents diagnostic challenges involved during the course of her management and accurate use of preoperative tools, which helped in the diagnosis of the case before the definitive treatment.

Multi-Disciplinary Management of Hidradenocarcinoma

Hidradenocarcinoma makes up 6% of eccrine malignancies, and is an uncommon eccrine sweat gland tumour. The etiology is due to genetic alterations and transformation from an existing lesion or hidradenoma. It typically affects the face and scalp, although it can also cause nodal involvement and show up on the trunk, abdomen, or groin. Due to its similarities to other skin tumours, it is challenging to diagnose histopathologically. Therefore, immunohistochemical markers, such as p53, Ki-67, keratin AE1/AE3, and cytokeratin 5/6, are crucial for the diagnoses. There are no prospective randomized trials available to direct treatment of hidradenocarcinoma. A key component of therapy is early diagnoses and case discussion in multidisciplinary tumor board. Wide local excision with clear margins is the mainstay of treatment. Adjuvant treatment like chemo radiation therapy is incorporated if nodal disease or positive margins are present. Recurrences are treated by re-excision followed by adjuvant radiation therapy. Adjuvant hormonal therapy depends on the receptor status of the disease. These tumors have a 50% recurrence rate and up to 60% of the time they metastasize to the brain, bone, lung, liver, mediastinum, or peritoneum in a two-year period. The overall five year survival rate is around 30%. Keeping in view the aggressive course of this disease, research based clinically evident new treatment strategies are the need of time to optimize overall survival and local disease control. Keywords: Sweat gland tumors, Adnexal tumors, Hidradenocarcinoma, Adjuvant therapy, Multidisciplinary team, Radiation therapy.

Gene fusions in poroma, porocarcinoma and related adnexal skin tumours: An update.

Poroma is a benign sweat gland tumour showing morphological features recapitulating the superficial portion of the eccrine sweat coil. A subset of poromas may transform into porocarcinoma, its malignant counterpart. Poroma and porocarcinoma are characterised by recurrent gene fusions involving YAP1, a transcriptional co-activator, which is controlled by the Hippo signalling pathway. The fusion genes frequently involve MAML2 and NUTM1, which are also rearranged in other cutaneous and extracutaneous neoplasms. We aimed to review the clinical, morphological and molecular features of this category of adnexal neoplasms with a special focus upon emerging differential diagnoses, and discuss how their systematic molecular characterisation may contribute to a standardisation of diagnosis, more accurate classification and, ultimately, refinement of their prognosis and therapeutic modalities.

Sweat Gland Tumors Arising on Acral Sites: A Molecular Survey.

Recurrent oncogenic drivers have been identified in a variety of sweat gland tumors. Recently, integration of human papillomavirus type 42 (HPV42) has been reported in digital papillary adenocarcinoma (DPA). The main objectives of the present study were (i) to provide an overview of the prevalence of previously identified oncogenic drivers in acral sweat gland tumors and (ii) to genetically characterize tumors in which no recurrent genetic alteration has been identified yet. Cases of acral sweat gland tumors were identified from the database of the French network CARADERM. After histologic review, the presence of previously identified genetic alterations was investigated in the entire cohort (n=79) using a combination of immunohistochemistry and targeted DNA and RNA sequencing. Tumor entities with no recurrent genetic alterations were submitted to whole-transcriptome sequencing. CRTC1::MAML2 fusion was identified in cases of hidradenoma and hidradenocarcinoma (n=9/12 and n=9/12). A p.V600E mutation of BRAF was observed in all cases of tubular adenoma (n=4). YAP1:MAML2 and YAP1::NUTM1 fusions were observed in poroid tumors (n=15/25). ETV6::NTRK3 and TRPS1::PLAG1 fusion transcripts were identified in secretory carcinoma (n=1/1) and cutaneous mixed tumors (n=3/4), respectively. The HPV42 genome was detected in most cases of DPA (n=10/11) and in 1 adnexal adenocarcinoma not otherwise specified. Finally, whole-transcriptome analysis revealed BRD3::NUTM1 or NSD3::NUTM1 fusions in 2 cases of NUT adnexal carcinoma and NCOA4::RET and CCDC6::RET fusion transcripts in 2 cystadenoma/hidrocystoma-like tumors. Our study confirms distinctive cytogenetic abnormalities in a wide number of acral adnexal neoplasms and supports the use of molecular analysis as a valuable aid in the diagnosis of these rare and often difficult to diagnose group of neoplasms.

Digital Papillary Adenocarcinoma in Nonacral Skin: Clinicopathologic and Genetic Characterization of 5 Cases.

Digital papillary adenocarcinoma (DPA) is a rare sweat gland neoplasm that has exceptionally been reported outside acral locations. Recently, human papillomavirus 42 was identified as the main oncogenic driver of DPA. Herein, we report 5 tumors arising in extra-acral locations predominantly in the female anogenital skin. Four patients were female and 1 patient was male. The mean age at the diagnosis time was 65 years (range: 55 to 82y). Tumors were located on the vulva (n=3), perianal area (n=1), and forearm (n=1). Histologically, all tumors were lobular and mainly solid and composed of sheets of cells with rare focal papillae and frequent glandular structures in a "back-to-back" pattern and lined by atypical basophilic cells. Immunohistochemistry showed diffuse positivity for SOX10. Epithelial membrane antigen and carcinoembryonic antigen highlighted the luminal cells and staining for p63 and p40 revealed a consistent and continuous myoepithelial component around glandular structures. Follow-up was available in 3 cases (mean duration: 12mo [range: 8 to 16mo]). One patient developed local recurrence and 1 experienced regional lymph node metastases. HPV Capture Next-generation sequencing revealed the presence of the HPV42 genome in all samples. Viral reads distributions were compatible in the 5 cases with an episomal nature of the viral genome, with a recurrent deletion in the E1 and/or E2 open reading frames. In conclusion, this study demonstrates that digital DPA may rarely present in nonacral locations mainly in the female anogenital area, usually with a more solid pattern as compared with those cases presenting on the digits and it is also associated with HPV42.

Porocarcinoma of the Left Foot: A Case Review.

Eccrine porocarcinoma is a rare malignant tumor of the eccrine sweat gland. This malignancy occurs most commonly in the lower extremities. It tends to occur in patients aged 60 to 80 years, affecting men and women equally. We present the case of a 62-year-old man with a lesion on the left foot. The diagnosis of the initial biopsy was squamous cell carcinoma. Six months later, the lesion reoccurred, and a second biopsy confirmed it to be eccrine porocarcinoma.

DP24 A case of digital papillary adenocarcinoma linked to human papillomavirus-42

Abstract A 60-year-old man with known stage-4 non-small cell lung cancer (NSCLC) and previous right-thumb hidradenoma presented with a 5-month history of a growing vascular lesion on his right great toe. Histology revealed a digital papillary adenocarcinoma (DPA) and positive quantitative polymerase chain reaction (qPCR) for human papilloma virus (HPV)-42 (courtesy of Thomas Wiesner’s research team in Austria). Review of previous histology for the lung and thumb lesions showed histological features consistent with DPA. He re-presented after 2 years with metastatic DPA in his right posterior calf. Following wide local excision (WLE), this locally reoccurred, requiring further excision. Aside from chemotherapy for NSCLC, he was not immunosuppressed and had no history of HPV-related disease. Digital papillary adenocarcinoma is a rare and aggressive neoplasm of sweat glands. Despite being a low-grade tumour, the rates of metastases and reoccurrence are high. Distant metastases are common and can present years after initial presentation. Distant metastases without lymph node spread have been reported. The annual incidence in the USA is ~0.08 cases per 1 000 000, typically presenting in men aged 50–70 years as a solitary lesion on the digits. It can invade muscle, tendons and bone. Owing to its rarity, misdiagnosis and treatment delay are common (Kobayashi T, Hiura A, Oishi K et al. Aggressive digital papillary adenocarcinoma with multiple organ metastases: a case report and review of the literature. Am J Dermatopathol 2016; 38:910–14). Studies show a link between HPV-42 and DPA, with qPCR detecting HPV-42 in known DPA cases (HPV-42 negative in hidradenoma). Human papilloma virus-42 was previously unknown to be oncogenic, and HPV vaccines do not target HPV-42 (Leiendecker L, Neumann T, Jung PS et al. Human papillomavirus 42 drives digital papillary adenocarcinoma and elicits a germ cell-like program conserved in HPV-positive cancers. Cancer Discov 2022; 13:70–84). There are no clear management guidelines and no drug therapy for DPA. Case studies have shown chemotherapy to be ineffective. Management is surgical with either amputation or WLE to avoid reoccurrence or metastases (Leiendecker et al.). Clinical suspicion for DPA should be high given its aggressive nature with regular long-term follow-up to detect reoccurrence or metastases early. More research is required on the epidemiology of this rare tumour in the UK and Europe and on treatment strategy beyond surgical resection, targeting the link between HPV-42 and DPA.

Eccrine Porocarcinoma of the Vulva With Sarcomatoid Transformation, a New Human Papillomavirus-associated Malignancy? Case Report and Review of the Literature.

Eccrine porocarcinoma is a rare cutaneous neoplasm, and rarer still in the anogenital region. In the vulva, the most common carcinoma by far is squamous cell carcinoma; however, eccrine porocarcinoma can arise at this site. As the distinction between porocarcinoma and squamous cell carcinoma has important prognostic implications at other cutaneous sites, it stands to reason that it may have these same implications in the vulva. We present a case of an eccrine porocarcinoma in the vulva of a 70-year-old woman that, in addition, showed sarcomatoid transformation. This tumor harbored human papillomavirus-18 DNA and mRNA, raising the question of the role of the oncogenic virus in sweat gland neoplasms of the vulva.

Acral BRAF‐mutated tubular adenoma should be distinguished from HPV42‐related digital papillary adenocarcinoma

Acral <i>BRAF</i>‐mutated tubular adenoma should be distinguished from <scp>HPV42</scp>‐related digital papillary adenocarcinoma

Clinicopathological Spectrum of Benign Skin Adnexal Tumors in the Pakistani Population: A Single-Center Study.

Background Skin adnexal tumors (SATs) are categorized per the site of origin, for example, hair follicles, sebaceous glands, and sweat glands. In our population, there is limited information related to the clinicopathological characteristics of these tumors. Management and prognosis depend largely upon the morphological type of the tumor. In this study, we assessed the disease spectrum and most prevalent subtypes of benign SATs. Methodology An analysis of 565 cases was conducted in this cross-sectional study between January 2018 and December 2022, using a non-probability consecutive sampling approach. Patient age, gender, site of involvement, and diagnosis were documented according to the fourth edition of the WHO Classification of Skin Tumors published in 2018. Data were entered and analyzed using SPSS Version 26.0 (IBM Corp., Armonk, NY). Results Our study had 565 patients, out of which 271 (47.9%) were males and 294 (52.1%) were females. The mean age was 40.97±19.3 years (range, 2-100 years). Anatomical site variations were as follows, head and neck (n=336, 59.4%), extremities (n=124, 22%), trunk (n=84, 14.9%), and genital areas (n=21, 3.7%). The most common histological subtypes of benign SATs were sweat gland origin (n=350, 62.0%), followed by hair follicle origin (n=161, 28.5 %), and sebaceous gland origin (n=54, 9.5%). Conclusion Sweat gland tumors were the most prevalent class of benign SATs in our study, in which hidradenoma and poroma were the most frequent subtypes. Hair follicle origin was the second most prevalent class of tumors with pilomatricoma being the most frequent. Sebaceous tumors were overall uncommon; nevus sebaceous of Jadasshon was the most common tumor in this class.