American Journal of Dermatopathology最新文献

{"title":"Recurrent Primary Cutaneous Anaplastic Large Cell Lymphoma With T-Cell Receptor-ϒδ Phenotype and DUSP22-IRF4 Unbalanced Rearrangement: A Rare and Diagnostically Challenging Presentation.","authors":"Elsayed Ibrahim, Woo Cheal Cho, Gokce Altay Toruner, Auris Huen, Carlos A Torres-Cabala, Jonathan L Curry","doi":"10.1097/DAD.0000000000003431","DOIUrl":"https://doi.org/10.1097/DAD.0000000000003431","url":null,"abstract":"<p><strong>Abstract: </strong>Primary cutaneous anaplastic large cell lymphoma (pcALCL) is an indolent CD30+ T-cell lymphoma, typically of T-cell receptor (TCR)-αβ origin with an excellent prognosis. Rare cases may exhibit a TCR-ϒδ phenotype or rearrangement of the DUSP22 and IRF4 genes on chromosome 6p25.3, but the concurrence of both features is exceedingly rare. We present herein a case of a 78-year-old man with a history of pcALCL who, 5 years after achieving complete remission with radiation therapy, experienced a recurrent neck nodule. Histopathological examination revealed a dense dermal infiltrate of medium to large atypical lymphoid cells. The lesion was strongly positive for CD30, TCR-δ, and LEF1 but negative for CD4, CD8, CD7, TCR-β, and ALK, and TIA-1. p-STAT3 was predominantly negative with labeling of few scattered cells. Fluorescence in situ hybridization studies confirmed a DUSP22-IRF4 abnormality. In view of immunohistochemical findings (LEF1+, TIA-1-, predominantly p-STAT3-), an unbalanced DUSP22-IRF4 rearrangement was favored. A diagnosis of pcALCL with TCR-ϒδ phenotype and DUSP22-IRF4 unbalanced rearrangement was rendered. This case adds to the small but growing number of reported cases of pcALCL with TCR-ϒδ phenotype and DUSP22-IRF4 alteration.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary Cutaneous Blastomycosis of the Nose After Arboreal Inoculation: Molecular Diagnosis by Fungal PCR and Next-Generation Sequencing.","authors":"Yan Li, Rodrigo Martinez Monedero, Linda Hu","doi":"10.1097/DAD.0000000000003420","DOIUrl":"https://doi.org/10.1097/DAD.0000000000003420","url":null,"abstract":"<p><strong>Background: </strong>Blastomycosis, caused by Blastomyces dermatitidis and the closely related Blastomyces gilchristii, is a systemic mycosis endemic to the Great Lakes region and the Mississippi and Ohio River valleys. Primary cutaneous blastomycosis from direct inoculation-without pulmonary or systemic involvement-is rare, with fewer than 50 cases reported in the literature. Diagnosis is particularly challenging when histochemical stains are negative and the tissue reaction pattern mimics squamous cell carcinoma.</p><p><strong>Case presentation: </strong>A 39-year-old immunocompetent African American man presented with a progressive verrucous nasal mass after facial trauma sustained from a tree branch. Skin biopsy revealed prominent pseudoepitheliomatous hyperplasia with epidermal breakdown and granulomatous inflammation. The degree of epithelial hyperplasia with surface disruption raised initial concern for well-differentiated squamous cell carcinoma. Both Periodic Acid-Schiff (PAS) and Grocott-Gomori methenamine silver stains were initially reported as negative for fungal organisms.</p><p><strong>Results: </strong>Fungal polymerase chain reaction with reflex next-generation sequencing performed on formalin-fixed paraffin-embedded tissue identified Blastomyces dermatitidis/gilchristii DNA, establishing a definitive diagnosis. Directed by this molecular result, retrospective review of the PAS stain identified a single yeast form morphologically consistent with Blastomyces, confirming that the initial organism burden was at the threshold of histochemical detection. Chest imaging and immunologic evaluation excluded pulmonary and systemic disease, supporting primary cutaneous inoculation blastomycosis. Treatment with itraconazole 200 mg twice daily resulted in significant reduction of the nasal lesion at 4-month follow-up.</p><p><strong>Conclusion: </strong>This case illustrates 3 diagnostic pitfalls in cutaneous blastomycosis. First, prominent pseudoepitheliomatous hyperplasia with epidermal breakdown can closely mimic well-differentiated squamous cell carcinoma, a well-recognized but underappreciated histologic confounder. Second, PAS and Grocott-Gomori methenamine silver stains may be falsely negative when organism burden is extremely low, as demonstrated by the identification of only a single yeast form on directed retrospective review. Third, fungal polymerase chain reaction with next-generation sequencing reflex from formalin-fixed paraffin-embedded tissue is a critical diagnostic tool when conventional histochemical methods and morphologic assessment are inconclusive. Primary cutaneous lastomycosis should remain in the differential diagnosis of verrucous facial lesions after penetrating trauma, even in immunocompetent patients.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148892875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary Cutaneous Apocrine Carcinoma and Basal Cell Carcinoma Arising in a Nevus Sebaceous of Jadassohn: Case Report and Literature Review.","authors":"Polina R Khaibullina, Dmitry N Serov, Ilya G Asinovskov, Kseniya Y Fedotova, Svetlana Y Solovyova, Ekaterina O Lekarevich, Ihar I Haiduk","doi":"10.1097/DAD.0000000000003415","DOIUrl":"https://doi.org/10.1097/DAD.0000000000003415","url":null,"abstract":"<p><strong>Abstract: </strong>Nevus sebaceous of Jadassohn (NSJ) is a congenital organoid hamartoma composed of epidermal, follicular, sebaceous, and apocrine elements that may give rise to secondary neoplasms later in life. Although most tumors arising in NSJ are benign adnexal proliferations, malignant neoplasms may occasionally develop. We report a case of a 56-year-old female patient with a long-standing lesion on the parietal scalp. Histopathologic examination revealed NSJ associated with 2 distinct malignant neoplasms: primary cutaneous apocrine carcinoma and superficial basal cell carcinoma. The diagnosis of apocrine carcinoma was established based on the morphologic findings and clinicoradiologic evaluation to exclude an internal primary malignancy. This case highlights the pluripotential nature of nevus sebaceous and underscores the importance of careful histopathologic evaluation of long-standing lesions that develop a new nodular component. This is particularly important as multiple and even malignant neoplasms may arise within a single lesion.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148888662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melanotrichoblastoma: Two Cases with Expanded Histopathologic and Immunophenotypic Features.","authors":"Yan Zhou, Lina Hu","doi":"10.1097/DAD.0000000000003418","DOIUrl":"https://doi.org/10.1097/DAD.0000000000003418","url":null,"abstract":"<p><strong>Abstract: </strong>Melanotrichoblastoma is an exceptionally rare benign follicular neoplasm recognized by the fifth edition of the WHO classification as a heavily pigmented variant of trichoblastoma. It is characterized by a prominent proliferation of basaloid follicular germinative cells intimately colonized by active dendritic melanocytes, alongside significant stromal and intratumoral melanin deposition. Owing to its dense pigmentation and basaloid morphology, it is frequently mistaken for pigmented basal cell carcinoma, melanoma, or other pigmented adnexal tumors. We report 2 cases occurring in women aged 43 and 79 years involving the scalp and cheek, respectively. Both lesions were well-demarcated dermal neoplasms composed of basaloid nests and cords lacking epidermal connection. Architectural patterns included solid, reticulated, cribriform, and cystic areas with focal follicular keratin cyst formation. Numerous dendritic melanocytes colonized the epithelial nests, successfully verified via red chromogen SOX10 and Melan-A staining. Both tumors showed diffuse AE1/AE3 and BER-EP4 positivity, wildtype p53 expression, and highly variable CK7/CD10 staining. These cases expand the limited literature and reinforce that diagnosis depends primarily on recognition of the characteristic epithelial-melanocytic architecture, rather than a rigid reliance on single ancillary immunohistochemical markers. Awareness of this rare variant is essential to avoid diagnostic pitfalls and patient overtreatment.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148882500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic and Prognostic Values of PRAME Immunohistochemistry in Acral Lentiginous Melanoma.","authors":"Korn Triyangkulsri, Namthong Wittayabusarakam, Supachak Smitthisakda, Nawara Sakpuwadol, Kunlawat Thadanipon, Bantita Phruttinarakorn, Suthinee Rutnin","doi":"10.1097/DAD.0000000000003305","DOIUrl":"10.1097/DAD.0000000000003305","url":null,"abstract":"<p><strong>Background: </strong>PReferentially Expressed Antigen in MElanoma (PRAME) was introduced as an ancillary tool for confirming the diagnosis of cutaneous melanoma, including the acral lentiginous melanoma (ALM). However, its standardized cut-off values and prognostic performance remain inconclusive. This study assessed the diagnostic performance of PRAME immunohistochemistry (IHC) in ALM across different thresholds and explored its prognostic associations.</p><p><strong>Methods: </strong>This retrospective cohort study reviewed 90 acral melanocytic lesions, including 60 cases of acral benign nevi and 30 cases of primary ALM. PRAME immunohistochemistry was performed on the biopsy specimens. Sensitivity and specificity were calculated at varying cut-offs. The optimal threshold was applied to link PRAME expression with the outcome and features of ALM.</p><p><strong>Results: </strong>A PRAME staining threshold of 50% (score ≥3) provided the optimum cut-off for differentiating ALM, with a high specificity of 98.3% and sensitivity of 53.3%. Positive PRAME was significantly associated with higher TNM stages (ordinal odds ratio [95% confidence interval], 13.11 [2.55-67.27]) and higher rates of recurrence (hazard ratio, 6.62 [1.42-30.94]) but not with any unfavorable histopathological features or mortality.</p><p><strong>Conclusion: </strong>PRAME can be used as an adjunctive diagnostic tool to differentiate malignant from benign acral melanocytic lesions. It may serve as a prognostic marker for poor ALM outcomes.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":"684-690"},"PeriodicalIF":0.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13489763/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148037374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EZH2 Upregulation Reflects Proliferation and Disease Stage in Mycosis Fungoides.","authors":"Aslı Aksu, Deniz Altınel, Semih Arslan, Ayberk Aktaran, Pinar Ozdemir Cetinkaya, Birgül Özkesici Kurt, Hazel Ezgi Kaya, İlknur Altunay","doi":"10.1097/DAD.0000000000003316","DOIUrl":"10.1097/DAD.0000000000003316","url":null,"abstract":"<p><strong>Abstract: </strong>Enhancer of Zeste Homolog 2 (EZH2) , the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2), mediates histone H3 lysine 27 trimethylation (H3K27me3) and plays an important role in epigenetic transcriptional repression and oncogenesis. Although EZH2 mutations are well characterized in B-cell lymphomas, its role in cutaneous T-cell lymphomas, including mycosis fungoides (MF), remains incompletely understood. The aim of this study was to evaluate EZH2 expression in MF using immunohistochemistry and to investigate its association with clinicopathologic parameters and proliferative activity. A total of 46 patients with MF were retrospectively analyzed. The cohort comprised 41 patients with early-stage disease (IA-IB) and 5 patients with more advanced disease manifestations (plaque and tumor lesions, including stage IIB cases). Nuclear EZH2 expression was semiquantitatively scored, and the Ki-67 proliferation index was assessed. Associations between EZH2 expression and clinicopathologic variables were analyzed using nonparametric statistical tests, including the Kruskal-Wallis and Spearman correlation tests. EZH2 expression increased progressively with advancing disease stage and lesion morphology ( P < 0.05). A significant positive correlation was observed between EZH2 expression and disease stage (r = 0.342; P = 0.02), and with the Ki-67 proliferation index (r = 0.575; P < 0.001). EZH2 expression showed no significant association with serum lactate dehydrogenase levels, β 2 -microglobulin levels, age, sex, or disease duration. The relatively small sample size, particularly the limited number of advanced-stage cases, and the retrospective design represent study limitations. These findings demonstrate that EZH2 expression parallels disease progression and proliferative activity in MF and suggest that EZH2 immunohistochemistry may serve as a useful adjunct marker reflecting biological disease activity in routine dermatopathologic evaluation.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":"705-709"},"PeriodicalIF":0.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148334219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary Oral MALT Lymphoma Without Nodal or Systemic Involvement: A Rare Presentation.","authors":"Elen de Souza Tolentino, Mariane Cordeiro Dos Santos, Ana Regina Casaroto Moreschi, Heliton Gustavo de Lima, Fábio Vieira de Miranda, Camila Lopes Cardoso","doi":"10.1097/DAD.0000000000003318","DOIUrl":"10.1097/DAD.0000000000003318","url":null,"abstract":"<p><strong>Abstract: </strong>Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a low-grade B-cell lymphoma, whose primary manifestation in the oral cavity is exceedingly rare. Owing to its nonspecific clinical presentation and histopathological overlap with benign inflammatory or reactive lesions, the diagnosis of MALT lymphoma can be challenging. We report the case of a middle-aged patient presenting with a slow-growing, asymptomatic oral lesion initially suspected to be an oral lipoma. Histopathological examination, complemented by immunohistochemical analysis, confirmed the diagnosis of primary oral MALT lymphoma. This report highlights the diagnostic challenges associated with oral lymphoid proliferations and underscores the critical importance of clinicopathological correlation for achieving an accurate diagnosis and ensuring appropriate management.</p>","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":"720-724"},"PeriodicalIF":0.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148334281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum: Cutaneous Involvement by Diffuse Large B-Cell Lymphoma With Dual B-Cell and T-Cell Clonality and Heavy Admixed T-Cell Infiltrate: Answer.","authors":"Nada Shaker, Robert Phelps, Carlos Torres-Cabala, George Niedt, Omar P Sangueza, Dinesh Pradhan","doi":"10.1097/DAD.0000000000003250","DOIUrl":"10.1097/DAD.0000000000003250","url":null,"abstract":"","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":"750"},"PeriodicalIF":0.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148334200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraepidermal Merkel Cell Carcinoma in Association With Squamous Cell Carcinoma In Situ and Adjacent Invasive Merkel Cell Carcinoma.","authors":"Federico Repetto, Eleanor E Russell-Goldman, Christine G Lian, Mia S DeSimone","doi":"10.1097/DAD.0000000000003346","DOIUrl":"10.1097/DAD.0000000000003346","url":null,"abstract":"","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":"e88-e90"},"PeriodicalIF":0.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148334164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From Readability to Reliability: Audit-Ready, Equity-Aware Simplification of Dermatopathology Reports.","authors":"Anjali Sharma, M Vijayasimha, Rajesh P Jayaswal, Vasudha Kapani","doi":"10.1097/DAD.0000000000003271","DOIUrl":"10.1097/DAD.0000000000003271","url":null,"abstract":"","PeriodicalId":50967,"journal":{"name":"American Journal of Dermatopathology","volume":" ","pages":"744-745"},"PeriodicalIF":0.8,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148334217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}