[A Case Report of Adenomyoepithelioma Coexisting with Apocrine Carcinoma in Contralateral Breasts].

Adenomyoepithelioma(AME)of the breast is a rare condition, and comorbidity with carcinoma is even more unusual. Herein, we report a case of both AME and apocrine carcinoma in different breasts of a single patient. A 48-year-old woman presented to our clinic with a right breast tumor. Fine needle aspiration cytology(FNAC)was indeterminate and suspicious for both papilloma and non-invasive ductal carcinoma, but excisional biopsy indicated an AME. Immuno-histochemical staining showed EMA(+), AE1/3(+), and CK7(+)mammary duct cells and αSMA(+), CK5/6(+), and p63(+) myoepithelial cells. Six months later, the patient noticed a left breast tumor, and although FNAC indicated no malignancy, after 6 additional months, the tumor size had increased and a mammography revealed tumor microcalcification, suggesting malignancy. Vacuum-assisted biopsy revealed an apocrine carcinoma. The patient underwent partial mastectomy and sentinel node biopsy, followed by radiotherapy and chemotherapy. The post-surgical pathology was pT1pN0M0, Stage Ⅰ, triple- negative, and the patient was disease-free for 12 years postoperatively. To our knowledge, this is only the second case of AME and breast cancer in different breasts reported in Japan.

Pedunculated eccrine poromas on non-acral sites.

A woman in her mid-50s, a patient with metastatic right breast carcinoma, postradical mastectomy and chemoradiation on hormonal therapy, presented with asymptomatic reddish lesions over the neck and trunk. Cutaneous examination revealed three discrete pedunculated, non-tender, firm erythematous growths with smooth surfaces over the neck, chest and abdomen. Histopathological examination was done with the differentials of pyogenic granuloma, haemangioma, giant acrochordon and vascular metastasis, revealing the diagnosis of eccrine poroma (EP). The remaining lesions were removed by electrocautery with no relapse till 1 year of follow-up. EP is a rare benign neoplasm arising from the acrosyringium that commonly presents as solitary, sessile or pedunculated asymptomatic papules or nodules over the palms and soles. Here we report the rare occurrence of multiple pedunculated EPs on a non-acral site in a patient who received chemoradiotherapy, which clinically mimicked pyogenic granuloma and vascular metastases. Thus, emphasising the importance of considering EP as a differential in lesions with vascular morphology.

Inverse Eruptive Syringoma in a Skin of Color Patient.

Syringomas are benign neoplasms derived from eccrine sweat glands. Eruptive syringomas are a subtype of syringomas and are typically located on the chest, neck, and abdomen during puberty or childhood. Herein, we present a 20-year-old African American female with an atypical case of eruptive syringomas, characterized by an unusual distribution on her chest, abdomen, and anterior and posterior bilateral extremities. This case underscores the importance of recognizing diverse presentations of skin conditions in patients with skin of color and adds to the limited reports of eruptive syringoma in these populations. We present and emphasize this atypical manifestation of eruptive syringomas in an individual with darker skin to promote awareness and improve diagnosis and patient outcomes.J Drugs Dermatol. 2024;23(7):564-566. doi:10.36849/JDD.8103.

Squamoid eccrine ductal carcinoma: clinical, histological and immunohistochemical features.

Squamoid eccrine ductal carcinoma (SEDC) is a cutaneous adnexal malignancy that is histologically challenging to distinguish from squamous cell carcinoma. We report three cases of this rare entity and review the present literature regarding clinical, histological, and immunohistochemical features. Patients presented with a single nodule or plaque lesion on their back and temple. The shave biopsies for Patient A and C were interpreted as SEDC. Patient B's initial shave biopsy was interpreted as probable surface of squamous cell carcinoma, and subsequent excision revealed SEDC. Ductal differentiation was confirmed by positive expression of epithelial membrane antigen and carcinoembryonic antigen immunostains in all three patients. Review of the 67 previously reported cases emphasizes the importance of diagnosing SEDC accurately and promptly given its potential for distant metastasis and mortality. Perineural or lymphatic invasion is associated with higher rate of recurrence or metastasis. There should be high pathologic suspicion for SEDC in an elderly patient presenting with a palpable lesion, even if located outside of the head and neck area, particularly when there is suggestion of ductal differentiation in a sample of a squamous neoplasm.

Nodular hidradenoma: clinical, dermoscopic, and histopathological features.

Nodular hidradenoma is an infrequent benign tumor originating from the proximal portion of the sweat glands, most commonly associated with the apocrine glands. Owing to its variable clinical presentation, correctly diagnosing nodular hidradenoma can be challenging, with several potential conditions in the differential diagnosis to consider. This article presents a healthy 52-year-old woman with an atypical location of nodular hidradenoma, highlighting the critical role of integrating clinical, dermoscopic, and histopathological characteristics for an accurate diagnosis. We discuss the clinical features, dermoscopic findings, histological examination, differential diagnosis, and treatment options for nodular hidradenoma, emphasizing the importance of surgical intervention in preventing potential malignant transformation.

Hidrocystoma-like tumours with RET or ALK fusion: a study of four cases.

Hidrocystoma is thought to be a benign retention cyst of sweat ductal units. The lesion is usually located in the periorbital skin; however, lesions with similar histopathological features are rarely observed in extra-facial sites. Herein, we present four cases of hidrocystoma-like tumours in extra-facial skin sites that harboured a RET or ALK rearrangement. This study features a 67-year-old female with a 10 mm-sized digital tumour (Case 1), a 62-year-old male with an 8 mm-sized clavicular tumour (Case 2), a 61-year-old male with a 19 mm-sized digital tumour (Case 3), and an 11-year-old female with a 10 mm-size lower leg tumour (Case 4) as well as five control cases (Cases 5-9) of classical periorbital hidrocystoma. In Cases 1-4, multicystic tumours comprising a two-cell layer of inner cuboidal ductoglandular (p63- and SOX10+/-) and outer flat myoepithelial (p63+ and SOX10+) cells were observed. The inner ductoglandular tumour cells exhibited micropapillary projections and Roman bridging structures. No apparent atypical cells were observed. NCOA4::RET in Cases 1 and 3, CCDC6::RET in Case 2, and SLC12A2::ALK in Case 4 were revealed by next-generation sequencing or Sanger sequencing. In contrast, control cases of classical hidrocystoma (Cases 5-9) did not show intracystic proliferation, abundant cytoplasm, ALK immunoreactivity, or NCOA4::RET detection in the tumour cells. RET/ALK-rearranged hidrocystoma-like tumours are tumour entities that can be distinguished from classical hidrocystoma. This RET/ALK-rearranged neoplasm is benign and is frequently observed in the digits. Future studies will establish the concept, detailed clinicopathological characteristics, and genetic variations of hidrocystoma-like tumours.

A Rare Case of Axillary Extramammary Paget's Disease with an Underlying Adenocarcinoma.

Extramammary Paget's disease (EMPD) is an uncommon cutaneous neoplasm almost exclusively located in the vulvar, perianal, and male genitalia regions. Evaluation and management are complicated given the average delay in diagnosis is two years and approximately 30% of cases are associated with underlying malignancies. The axilla is a unique location for EMPD. We report a rare case of a 78-year-old male with axillary EMPD associated with an underlying adenocarcinoma. A 1-cm tender and pruritic erythematous plaque with surrounding erythema appeared in the patient's axilla. An irritated seborrheic keratosis secondarily impetiginized along with irritant contact dermatitis was suspected. Treatment of cefdinir and topical hydrocortisone failed and a biopsy was taken. Microscopic and immunohistochemical examination showed ulceration with an underlying proliferation of atypical glands (Figure 2A) and a nested intraepidermal proliferation with pagetoid spread (Figure 2B). The atypical cells were positive for gross cystic disease fluid protein 15 (Figure 2C), epithelial membrane antigen (Figure 2D), cytokeratin 5/6, and cytokeratin 7. These findings were supportive of an apocrine adenocarcinoma arising in association with EMPD. Wide location excision was performed. Screening for associated malignancies or lymphatic spread is the primary goal during evaluation. Outcomes are favorable when the primary neoplasm is of limited distribution. The accepted treatment for primary lesions is wide local excision, although anatomic tissue constraints necessitate further research into other treatment modalities. To our knowledge, this is the 14th reported case of axillary EMPD with an underlying adenocarcinoma which may help with identification and management of future cases.

Clinical and morphological features of eccrine acrospiroma: analysis of literature data and case from practice.

Eccrine acrospiroma is a rare benign tumor of the skin arising from the epithelial cells of eccrine sweat ducts. The clinical picture is characterized by its variability, so a detailed morphological study of the operative material is necessary to establish a diagnosis. Differential diagnosis must be carried out with hemangioma, melanoma, infected sebaceous cyst, metastatic skin lesion, and other tumors from elements of the sweat gland. In the article the authors presented the clinical and morphological analysis of own case from practice of large eccrine acrospiroma on the back surface of the left thigh which was diagnosed in a 56-year-old man.

Syringomatous tumor of the nipple: a case report.

Syringomatous tumor of the nipple is a benign, locally infiltrative tumor. There are reports in the literature of tumor recurrence in cases of incomplete excision. Clinical and mammographic findings in syringomatous tumors are like those of breast carcinoma and the pathologist has a fundamental role in final tumor diagnosis. Therefore, the aim of this study was to report a case of syringoma located in the areolar region. A 33-year-old woman reported that she had noticed a nodule in her left areolar region 4 years previously (February 2019). A breast ultrasound was performed, detecting intraparenchymatous breast cysts. Surgical resection of the nodule was indicated although it was not performed. Two years later, in August 2021, the patient underwent a mastopexy with prosthesis inclusion. Histopathology study of the surgical specimen revealed a syringomatous tumor with positive margins. Thirteen (13) months after diagnosis (September 3, 2021 - October 16, 2022), the patient is doing well and receives clinical follow-up.

Porocarcinoma: Clinical and Histological Features, Immunohistochemistry and Outcomes: A Systematic Review.

Porocarcinoma (PC) is a rare adnexal tumor, mainly found in the elderly. The tumor arises from the acrosyringium of eccrine sweat glands. The risk of lymph node and distant metastasis is high. Differential diagnosis with squamous cell carcinoma is difficult, although NUT expression and YAP1 fusion products can be very useful for diagnosis. Currently, wide local excision is the main surgical treatment, although Mohs micrographic surgery is promising. To date, there is no consensus regarding the role of sentinel lymph node biopsy and consequential lymph node dissection. No guidelines exist for radiotherapy, which is mostly performed based on tumor characteristics and excision margins. Only a few studies report systemic treatment for advanced PC, although therapy with pembrolizumab and EGFR inhibitors show promise. In this review, we discuss epidemiology, clinical features, histopathological features, immunohistochemistry and fusion products, surgical management and survival outcomes according to stage, surgical management, radiotherapy and systemic therapy.

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

BACKGROUND AND OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Syringocystadenocarcinoma papilliferum: a systematic review of clinical characteristics, reappraisal of associations, diagnostic pitfalls and management challenges.

Syringocystadenocarcinoma papilliferum (SCACP) is a rare and aggressive malignant adnexal tumor originating from apocrine or pluripotent appendageal glands, often associated with a preceding syringocystadenoma papilliferum (SCAP) or nevus sebaceus (NS). This systematic review rigorously examines SCACP through an analysis of 78 cases documented between 1980 and 2024. The study aims to provide a comprehensive review of the clinical manifestations, diagnosis, treatment modalities, and outcomes associated with SCACP, while also reappraising its associations, particularly with NS. SCACP predominantly affects older adults, with an average age of 66.3 years and a slight male predominance, commonly presenting as ulcerated nodules or plaques on the scalp. This review highlights the aggressive nature of SCACP, evidenced by significant rates of metastasis and recurrence. Treatment is primarily surgical, with Mohs micrographic surgery offering potential benefits in terms of margin control and cosmetic outcomes. The association of SCACP with NS is critically evaluated, suggesting a complex etiopathogenesis and underscoring the importance of recognizing this association for timely diagnosis and management. Our review also briefly discusses potential pitfalls faced by clinicians in the diagnosis of SCACP. Our findings emphasize the need for standardized treatment protocols and further research into targeted therapies to improve patient outcomes in SCACP.

Intradermal Syringocystadenoma Papilliferum on the Popliteal Fossa: A Rare Dermal Variant in an Atypical Location.

Syringocystadenoma papilliferum (SCAP) is a benign adnexal tumor commonly found on the scalp and face, and often associated with nevus sebaceous, with about half of cases appearing in early childhood. SCAP exhibits cystic invaginations with papillary structures and a double-layered glandular epithelium linked to the epidermal surface and stromal plasma cells. We are reporting a rare instance of intradermal SCAP in a 55-year-old male. He sought evaluation for a long-standing asymptomatic dark-pink papule in his left popliteal fossa, measuring 0.7 x 0.5 x 0.4 cm. A shave biopsy revealed papillary dermal fibrosis, glandular epithelium with apocrine secretion, and papillary projections without an epidermal connection. Infundibulofollicular keratinization was observed, along with stromal plasma cells. The patient chose local excision as the treatment option. This case highlights the rarity of intradermal SCAP, especially in the left popliteal fossa, with only one other reported case in the literature.

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 Rare Case of Metastatic Spiradenocarcinoma With CDKN2A Mutation.

Spiradenocarcinomas are rare malignant skin adnexal tumors. We describe a novel case of a patient with an aggressive CDKN2A-mutated spiradenocarcinoma who responded to a CDK4/6 inhibitor. This case highlights the unique nature of spiradenocarcinomas as well as the potential benefit of targeted therapy.

Clear cell hidradenoma of the breast with MAML2 gene rearrangement.

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