暂无摘要。

Adnexal clear cell carcinoma exhibiting comedonecrosis (ACCCC) is a rare, cutaneous, malignant neoplasm with limited reported cases since its discovery. ACCCC is characterized by unique clinical and histological features, demanding a precise diagnosis due to its potential for aggressive behavior and early metastases, distinct from other cutaneous tumors with clear cytoplasmic cells. We present the case of an 81-year-old male with a history of multiple non-melanoma skin cancers, who presented with a 5 mm erythematous papule on his left tragus. Initial tangential shave biopsy results were invasive clear cell squamous cell carcinoma that was moderately differentiated. Subsequent Mohs micrographic surgery (MMS) necessitating a full-thickness skin graft reconstruction was performed. Histopathological examination afterward confirmed ACCCC with pleomorphic epithelial cells, clear cytoplasm, and central comedonecrosis. Immunohistochemistry supported adnexal differentiation and squamous features. To our knowledge, this is the fifteenth reported case of ACCCC as well as the first documented case of ACCCC treated with MMS, offering a novel approach to managing this rare malignancy.

暂无摘要。

Hidradenoma papilliferum (HP) is a benign adnexal tumor, commonly affecting the anogenital region of middle-aged women. Clinically, HP typically presents as a slow-growing, unilateral, well-circumscribed, smooth skin-colored cystic dermal nodule, usually growing less than 1 cm in size. Reports of ectopic HP are exceedingly rare but have been identified in areas containing modified apocrine gland structures, most commonly on the head and neck, and have included ceruminous glands of the external ear canal, the Moll glands of the eyelid, mammary glands of the breast, maxillofacial region and areas on the scalp. To the best of our knowledge, there is only one case of ectopic HP located on the external ear canal reported in English literature. We present a second case of draining ectopic HP located on the conchal bowl of the external ear canal.

Eccrine poroma is a rare benign adnexal tumor arising from intradermal cells of eccrine sweat ducts. At least two-thirds of eccrine poromas present on the extremities, most commonly on the palms and soles. They are scarcely found on the face; to date, only 11 cases of eyelid poromas have been reported in PubMed. Biopsy excision with a free margin is necessary to distinguish it from malignant lesions and avoid recurrence with possible transformation to porocarcinoma. We present the case of a 23-year-old male with a histopathological confirmation of poroma using staining with hematoxylin-eosin on the eyelid, previously clinically diagnosed with molluscum contagiosum. After four years, he has not experienced a recurrence.

Aim of the report: Brooke-Spiegler syndrome (BSS) is a rare autosomal dominant disease characterized by the growth of cylindromas, spiradenomas, trichoepitheliomas, or their combination. These neoplasms usually begin in the second decade and progressively increase in number and size over the years. Diagnosis necessitates consideration of family history, clinical examination, histological findings, and genetic analysis. The aim of this paper is to explore the clinical overlap between Brooke-Spiegler syndrome (BSS) and neurofibromatosis type 1 (NF1). We aim to highlight the challenges associated with their differential diagnosis and emphasize the lack of standardized diagnostic criteria and treatment approaches. Case presentation: Hereby, we introduce the case of a 28-year-old male referred for suspicion of neurofibromatosis type 1 (NF1) who initially declined the recommended surgical excision for a scalp mass. After four years, he returned with larger masses of the scalp, and underwent excision of multiple masses, revealing cylindromas, spiradenomas, and spiradenocylindromas. Family history reported similar tumors in his father, who was also diagnosed with NF1 for the presence of multiple subcutaneous lesions on the scalp. Clinical overlap led to a genetic consultation, but testing for CYLD mutations yielded no significant variations. Despite this, the strong family history and consistent findings led to a revised diagnosis of Brooke-Spiegler syndrome, correcting the initial misdiagnosis of NF1 syndrome. Conclusions: Thanks to the evolving landscape of BSS research over the past two decades, its molecular underpinnings, clinical presentation, and histopathological features are now clearer. However, a thorough family history assessment is mandatory when BSS is suspected. It is our belief that a multidisciplinary approach and cooperation between specialists are essential when dealing with BSS. By sharing this case, we hope to underscore the importance of considering BSS as a differential diagnosis, especially in cases with atypical presentations or overlapping features with other syndromes like NF1.

BACKGROUND: While the list of fusion-driven soft tissue neoplasms is expanding rapidly, their importance among cutaneous and superficial mesenchymal and adnexal neoplasms remains poorly understood. This challenge is especially evident in cases with ambiguous histopathology that are difficult to classify based on morphology.
OBJECTIVE: Our goal was to investigate the benefits of next-generation sequencing in diagnosing complex cutaneous neoplasms.
METHODS: Departmental archives were searched for fusion-driven cutaneous neoplasms. Slides were retrieved and clinical information including follow-up was obtained.
RESULTS: Fifteen cases occurred in eight female and seven male patients, with a median age of 26 years (range: 1-83) at diagnosis. Tumors involved the extremities (9), scalp (5), and head and neck (1). Predominant features included myoepithelial (5), nested spindled with clear cytoplasm (2), atypical adnexal/squamoid (2), small round blue cell (2), cellular spindled (3), and fibrohistiocytic morphology (1). Most frequently encountered fusions involved EWSR1 (6) fused to ERG (1), FLI1 (1), CREB1 (2), CREM (1), PBX3 (1), followed by PLAG1 (4) with LIFR (2), TRPS1 (1) and CHCHD7. Additional fusions encountered were YAP1::NUTM1, EML4::ALK, SS18::SSX1 (2), and a novel fusion: ACTB::ZMIZ2. Integration of histologic features and molecular findings led to final diagnoses of primary cutaneous Ewing sarcoma (2), soft tissue myoepithelioma (4), cutaneous syncytial myoepithelioma (1), cutaneous adnexal carcinoma (1), porocarcinoma (1), inflammatory myofibroblastic tumor (1), synovial sarcoma (2), clear cell sarcoma (2), and angiomatoid fibrous histiocytoma (1).
CONCLUSIONS: Our results show that fusion testing can be a helpful diagnostic tool, especially in cases with unusual or uncommon morphology in superficial sites. Furthermore, it can allow for the identification of potential therapeutic targets in some instances.

BACKGROUND: Primary cutaneous apocrine carcinomas of the axilla represents an extremely rare entity, with <200 cases reported in the literature. It can be challenging, even almost impossible, to distinguish histologically from metastases of breast origin. We herein present the first case of an axillary cutaneous apocrine adenocarcinoma followed and treated in our institute.
METHODS: A 58-year-old man with a history of myopathy, presented for a right axillary swelling. Physical examination revealed the presence of a 10 cm right axillary mass, no palpable adenopathy, and bilateral gynecomastia. A biopsy of the mass was performed, showing a pattern consistent with a secondary localization of mammary neoplasia. Breast and distant radiological examinations were negative. The tumor markers\' levels were not raised. Therefore, the patient underwent surgery with a large excision, a right axillary lymph node dissection, covered with a pedicled pectoralis major flap. Histological and immunohistochemical examinations showed a high expression of CK7 with a negative expression of TTF1, RH, PSA, and CK20. The diagnosis of an apocrine adenocarcinoma from cutaneous origin was confirmed.
UNASSIGNED: Primary cutaneous apocrine carcinomas are a group of uncommon malignant adnexal tumors, whose diagnosis is almost impossible to confirm preoperatively. Wide, local excision with clear margins, with or without lymph node dissection is the standard treatment.
CONCLUSIONS: This case illustrates the importance of clinico-pathological correlation of skin cancers, especially apocrine ones. Clinical particularity and careful histological analysis are used to guide the diagnostic approach.

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.

BACKGROUND: Although trichorhinophalangeal syndrome type 1 (TRPS1) was initially thought to be highly sensitive and specific for carcinomas and mesenchymal tumors of mammary origin, more recent data suggest its expression is not limited to breast neoplasms but also can be seen in other cutaneous neoplasms, such as extramammary Paget disease and squamous cell carcinoma (SCC) in situ.
METHODS: Two-hundred cases of non-melanocytic cutaneous neoplasm, including basal cell carcinomas (BCCs) (n = 41), SCCs (n = 35), Merkel cell carcinomas (MCCs) (n = 25), and adnexal neoplasms (n = 99), were tested for TRPS1 expression using a monoclonal anti- TRPS1 rabbit anti-human antibody.
RESULTS: TRPS1 expression was present in almost all cases of SCC (94%), with a median H-score of 200, while it was either absent or only focally present in most BCCs (90%), with a median H-score of 5. The difference between BCCs and SCCs in H-score was significant (p < .001). All MCCs (100%) lacked TRPS1 expression. TRPS1 expression was frequently seen in most adnexal neoplasms, benign and malignant, in variable intensity and proportion but was consistently absent in apocrine carcinomas. All endocrine mucin-producing sweat gland carcinomas (EMPSGCs) (100%, 6/6) showed diffuse and strong TRPS1 immunoreactivity, with a median H-score of 300, which was significantly different (p < .001) than that of BCCs.
CONCLUSIONS: Our study shows that TRPS1 may be an effective discriminatory marker for BCCs and SCCs. It also has a role in distinguishing BCCs from EMPSGCs.