This article reports the diagnosis and treatment process of a 65-year-old male patient diagnosed with xanthoma dissseminatum. The patient sought medical attention due to reddish brown patchy rashes on the skin of the arms, knees and abdomen. The results of positron emission tomography and computed tomography (PET/CT) suggested that non-Langerhans cell histiocytosis might involve multiple blood vessels, the skin of the posterior neck and right forearm, multiple soft tissues, the descending duodenum and possibly the spine. Biopsy on skin of right arm showed non-Langerhans cell proliferative changes, with a pathological diagnosis of xanthoma dissseminatum. The rash improved after 6 cycles of monotherapy with cladribine. Follow-up PET/CT results indicated that multiple foci of abnormally increased glucose metabolism in the skin, joints, and soft tissues had decreased compared to previous examinations, suggesting disease remission. After stopping medication for 9 months, the patient underwent PET/CT reexamination, which showed new bone lesions. Bone marrow puncture was performed which suggested xanthoma dissseminatum involvement. Subsequently, the patient received chidamide combined with cladribine. By January 2025, the third cycle of chemotherapy had been completed. The patient is still under follow-up.

Purpose To investigate the clinicopathological features and prognostic factors of follicular dendritic cell carcinoma(FDCS).Methods Hospital records of 23 patients diagnosed with FDCS were retrospectively re-viewed.The morphological,immunohistochemical features,including the detection of CD21,CD23,and CD35 using the EnVision method,and in-situ hybridization for Epstein-Barr virus encoded nuclear RNA(EBER)were evaluated.Clinicopathological characteristics were analyzed for the evaluation of prognosis.Results The median age of all 23 pa-tients was 50 years(range:27 to 72)and the female to male ratio was 1.3.The median maximum diameter of tumor was 7.0 cm(range:0.5 to 20.0 cm).One case was located in cervical lymph node,while another 22 were discovered in extranodal sites.20 cases were single organ and 3 cases were multiple organs involvement.Microscopically,tumor cells exhibited spindle,oval,or markedly pleomorphic morphology,accompanied by variable lymphoplasmacytic infil-tration in the stroma.CD21,CD35 and CD23 were positive in 22 of 23(95.6％),23 of 23(100.0％)and 4 of 15(26.7％)patients,respectively.EBER in-situ hybridization was positive in 9 of 23 patients(39.1％).The median follow-up time was 84.0(95％CI:50.7-117.3)months,and the 5-year survival rate was 80.2％(95％CI:62.8-97.6).Twelve(52.2％)patients were alive,5(21.7％)were dead,and 6(26.1％)were lost of follow-up.We es-tablished a pathological scoring system containing 5 indexes,i.e.,tumor maximum diameter,mitotic figures,tumor necrosis,cellular pleomorphism and histologic types.Patients with greater than 4 points had a significant poor progno-sis.Conclusion FDCS features a broad spectrum of histologic appearances and behavior.Combined morphological observations(HE staining),applications of a panel of follicular dendritic cell markers and EBER in-situ hybridization are helpful for accurate diagnosis.FDCS poses risks for recurrence,metastasis and death,and those with greater than 4 points in the scoring system have a significant poor prognosis.Long-term follow up is needed.

Purpose To explore the clinical and pathological features,differential diagnosis,treatment methods and prognosis of urachal adenocarcinoma.Methods Nineteen cases of urachal adenocarcinoma were collected and an-alyzed by combining clinical symptoms,auxiliary examinations,histology,immunohistochemical,and genetic testing and 11 cases of bladder adenocarcinomas.Results Among the 19 patients(15 males,4 females;age range:33-75 years,mean:55 years),tumors were located at the dome or anterior wall of the bladder.Histological subtypes includ-ed mucinous adenocarcinoma(6 cases),adenocarcinoma not otherwise specified(4 cases),enteric-type adenocarci-noma(6 cases),adenocarcinoma with focal mucinous differentiation(1 case),adenocarcinoma with signet-ring cell carcinoma(1 case),and metastatic urachal adenocarcinoma(1 case).Immunophenotypic analysis revealed membra-nous positivity for β-catenin,diffuse positivity for CK34βE 12,MUC-2,and CK20,focal CK7 positivity in some cases,and rare GATA-3 positivity.Mutations in p53 were observed,while KRAS,NRAS,BRAF,and PIK3CA mutations were absent.In colorectal adenocarcinomas,CK34βE12 positivity was 40％,nuclear β-catenin positivity was 48％,and MUC-2 expression was approximately 50％.In bladder adenocarcinomas,GATA-3 and MUC-2 positivity rates were 45％and 63.6％,respectively.Conclusion Distinguishing urachal adenocarcinoma from colorectal and primary bladder adenocarcinomas remains challenging.Urachal adenocarcinoma should be suspected in patients with anterior bladder wall or dome lesions,gross hematuria,or mucinuria.No definitive diagnostic markers currently exist for ura-chal adenocarcinoma.Immunophenotypic features such as membranous β-catenin,MUC-2,and CK7 positivity may fa-vor urachal adenocarcinoma over colorectal adenocarcinoma.Additional markers(e.g.,GATA-3,CK20,CK34βE12)aid in differential diagnosis,though individual markers lack specificity.Comprehensive evaluation integrating clinical presentation,imaging,and clinicopathological features is essential for accurate diagnosis.

Objective:To investigate the clinicopathological features, gene mutations, and distribution of bronchial adenoma (BA).Methods:Eighty-eight cases of BA diagnosed via routine section diagnosis between May 2015 and February 2024 were collected at the Pathology Departments of Zhongshan Hospital Affiliated to Fudan University (71 cases), Shanghai, China and Jining No.1 People′s Hospital (17 cases), Jining, China. Clinical data, image features, histopathological sections, immunohistochemical stains, and genetic testing results were reviewed.Results:Among the 88 patients with BA, there were 36 males and 52 females. The incidence of proximal-type BA was the same in both genders (50%, 28/56), while distal-type BA was more commonly found in females (75%, 24/32, P=0.022). BA predominantly affected middle-aged and elderly adults, with an age range of 30-78 years (median, 61 years). Clinically, BA generally presented without obvious symptoms. Radiologically it mainly manifested as peripheral lung ground-glass nodules, mixed ground-glass nodules, or solid nodules, primarily located in the lower lobes of the lungs (72.7%, 64/88). Proximal-type BA was characterized by solid nodules (53.6%, 30/56), while distal-type BA by ground-glass nodules (56.3%, 18/32), with a statistically significant difference between the two types ( P<0.01). The tumor was non-encapsulated, with a gray-white cut surface, and some areas were gray-brown. In 18.2% (16/88) of cases, the cut surface was slippery, with soft to medium-firm consistency and poorly defined margins. The smooth texture was predominantly found in proximal-type BA (14/16), whose tumor diameters ranged from 0.2 to 4.6 cm. Microscopically, the lesions exhibited glandular, papillary, or relatively flat patterns, with the main cellular components consisting of basal cells, ciliated columnar cells, mucinous cells, and alveolar epithelial cells in various proportions. Proximal-type BA resembled the morphology of proximal bronchioles and commonly contained mucinous and ciliated cells, while distal-type BA typically lacked mucinous and ciliated cells. The frequency of ciliated cell micropapillae in proximal-type BA (64.3%, 36/56) was significantly higher than that in distal-type BA (31.3%, 10/32, P=0.003). The morphological manifestation of glandular duct dilation was more commonly noted in proximal-type BA (98.2%, 55/56) than that in distal-type BA (81.25%, 26/32, P=0.009). Overall, the disagreement rate between frozen-section and routine diagnoses was 19.5% (17/87). Immunohistochemistry for cytokeratin 5/6 (CK5/6) and p40 showed that basal cell continuity in proximal-type BA (82.1%, 46/56) was significantly higher than that in distal-type BA (56.2%, 18/32, P=0.009). Molecular testing showed an accumulative gene mutation rate of 60.5% (23/38) in BA, including mutations in BRAF V600E (34.2%, 13/38), KRAS (18.4%, 7/38), ALK (5.3%, 2/38), and EGFR (2.6%, 1/38). Proximal-type BA was associated with BRAF V600E mutations, while distal-type BA with KRAS mutations ( P=0.025). Conclusions:BA is a rare benign bronchial tumor and has a high diagnostic error-rate on intraoperative frozen section. Proximal-type BA often presents with ciliated cell micropapillae, which supports the diagnosis, while distal-type BA frequently shows a partial reduction or absence of basal cells, increasing the diagnostic difficulty. The different subtypes of BA exhibit distinct genetic (mutation) profiles that may assist in its diagnosis and histological classification

Purpose To explore the clinical and pathological features,differential diagnosis,treatment methods and prognosis of urachal adenocarcinoma.Methods Nineteen cases of urachal adenocarcinoma were collected and an-alyzed by combining clinical symptoms,auxiliary examinations,histology,immunohistochemical,and genetic testing and 11 cases of bladder adenocarcinomas.Results Among the 19 patients(15 males,4 females;age range:33-75 years,mean:55 years),tumors were located at the dome or anterior wall of the bladder.Histological subtypes includ-ed mucinous adenocarcinoma(6 cases),adenocarcinoma not otherwise specified(4 cases),enteric-type adenocarci-noma(6 cases),adenocarcinoma with focal mucinous differentiation(1 case),adenocarcinoma with signet-ring cell carcinoma(1 case),and metastatic urachal adenocarcinoma(1 case).Immunophenotypic analysis revealed membra-nous positivity for β-catenin,diffuse positivity for CK34βE 12,MUC-2,and CK20,focal CK7 positivity in some cases,and rare GATA-3 positivity.Mutations in p53 were observed,while KRAS,NRAS,BRAF,and PIK3CA mutations were absent.In colorectal adenocarcinomas,CK34βE12 positivity was 40％,nuclear β-catenin positivity was 48％,and MUC-2 expression was approximately 50％.In bladder adenocarcinomas,GATA-3 and MUC-2 positivity rates were 45％and 63.6％,respectively.Conclusion Distinguishing urachal adenocarcinoma from colorectal and primary bladder adenocarcinomas remains challenging.Urachal adenocarcinoma should be suspected in patients with anterior bladder wall or dome lesions,gross hematuria,or mucinuria.No definitive diagnostic markers currently exist for ura-chal adenocarcinoma.Immunophenotypic features such as membranous β-catenin,MUC-2,and CK7 positivity may fa-vor urachal adenocarcinoma over colorectal adenocarcinoma.Additional markers(e.g.,GATA-3,CK20,CK34βE12)aid in differential diagnosis,though individual markers lack specificity.Comprehensive evaluation integrating clinical presentation,imaging,and clinicopathological features is essential for accurate diagnosis.

Objective:To investigate the clinicopathological features, gene mutations, and distribution of bronchial adenoma (BA).Methods:Eighty-eight cases of BA diagnosed via routine section diagnosis between May 2015 and February 2024 were collected at the Pathology Departments of Zhongshan Hospital Affiliated to Fudan University (71 cases), Shanghai, China and Jining No.1 People′s Hospital (17 cases), Jining, China. Clinical data, image features, histopathological sections, immunohistochemical stains, and genetic testing results were reviewed.Results:Among the 88 patients with BA, there were 36 males and 52 females. The incidence of proximal-type BA was the same in both genders (50%, 28/56), while distal-type BA was more commonly found in females (75%, 24/32, P=0.022). BA predominantly affected middle-aged and elderly adults, with an age range of 30-78 years (median, 61 years). Clinically, BA generally presented without obvious symptoms. Radiologically it mainly manifested as peripheral lung ground-glass nodules, mixed ground-glass nodules, or solid nodules, primarily located in the lower lobes of the lungs (72.7%, 64/88). Proximal-type BA was characterized by solid nodules (53.6%, 30/56), while distal-type BA by ground-glass nodules (56.3%, 18/32), with a statistically significant difference between the two types ( P<0.01). The tumor was non-encapsulated, with a gray-white cut surface, and some areas were gray-brown. In 18.2% (16/88) of cases, the cut surface was slippery, with soft to medium-firm consistency and poorly defined margins. The smooth texture was predominantly found in proximal-type BA (14/16), whose tumor diameters ranged from 0.2 to 4.6 cm. Microscopically, the lesions exhibited glandular, papillary, or relatively flat patterns, with the main cellular components consisting of basal cells, ciliated columnar cells, mucinous cells, and alveolar epithelial cells in various proportions. Proximal-type BA resembled the morphology of proximal bronchioles and commonly contained mucinous and ciliated cells, while distal-type BA typically lacked mucinous and ciliated cells. The frequency of ciliated cell micropapillae in proximal-type BA (64.3%, 36/56) was significantly higher than that in distal-type BA (31.3%, 10/32, P=0.003). The morphological manifestation of glandular duct dilation was more commonly noted in proximal-type BA (98.2%, 55/56) than that in distal-type BA (81.25%, 26/32, P=0.009). Overall, the disagreement rate between frozen-section and routine diagnoses was 19.5% (17/87). Immunohistochemistry for cytokeratin 5/6 (CK5/6) and p40 showed that basal cell continuity in proximal-type BA (82.1%, 46/56) was significantly higher than that in distal-type BA (56.2%, 18/32, P=0.009). Molecular testing showed an accumulative gene mutation rate of 60.5% (23/38) in BA, including mutations in BRAF V600E (34.2%, 13/38), KRAS (18.4%, 7/38), ALK (5.3%, 2/38), and EGFR (2.6%, 1/38). Proximal-type BA was associated with BRAF V600E mutations, while distal-type BA with KRAS mutations ( P=0.025). Conclusions:BA is a rare benign bronchial tumor and has a high diagnostic error-rate on intraoperative frozen section. Proximal-type BA often presents with ciliated cell micropapillae, which supports the diagnosis, while distal-type BA frequently shows a partial reduction or absence of basal cells, increasing the diagnostic difficulty. The different subtypes of BA exhibit distinct genetic (mutation) profiles that may assist in its diagnosis and histological classification

Purpose To investigate the clinicopathological features and prognostic factors of follicular dendritic cell carcinoma(FDCS).Methods Hospital records of 23 patients diagnosed with FDCS were retrospectively re-viewed.The morphological,immunohistochemical features,including the detection of CD21,CD23,and CD35 using the EnVision method,and in-situ hybridization for Epstein-Barr virus encoded nuclear RNA(EBER)were evaluated.Clinicopathological characteristics were analyzed for the evaluation of prognosis.Results The median age of all 23 pa-tients was 50 years(range:27 to 72)and the female to male ratio was 1.3.The median maximum diameter of tumor was 7.0 cm(range:0.5 to 20.0 cm).One case was located in cervical lymph node,while another 22 were discovered in extranodal sites.20 cases were single organ and 3 cases were multiple organs involvement.Microscopically,tumor cells exhibited spindle,oval,or markedly pleomorphic morphology,accompanied by variable lymphoplasmacytic infil-tration in the stroma.CD21,CD35 and CD23 were positive in 22 of 23(95.6％),23 of 23(100.0％)and 4 of 15(26.7％)patients,respectively.EBER in-situ hybridization was positive in 9 of 23 patients(39.1％).The median follow-up time was 84.0(95％CI:50.7-117.3)months,and the 5-year survival rate was 80.2％(95％CI:62.8-97.6).Twelve(52.2％)patients were alive,5(21.7％)were dead,and 6(26.1％)were lost of follow-up.We es-tablished a pathological scoring system containing 5 indexes,i.e.,tumor maximum diameter,mitotic figures,tumor necrosis,cellular pleomorphism and histologic types.Patients with greater than 4 points had a significant poor progno-sis.Conclusion FDCS features a broad spectrum of histologic appearances and behavior.Combined morphological observations(HE staining),applications of a panel of follicular dendritic cell markers and EBER in-situ hybridization are helpful for accurate diagnosis.FDCS poses risks for recurrence,metastasis and death,and those with greater than 4 points in the scoring system have a significant poor prognosis.Long-term follow up is needed.

Objective To summarize the pathological morphological features, diagnosis, and differential diagnosis of adult-onset Still disease (AOSD), and to improve clinical understanding of the disease. Methods A retrospective analysis was conducted on the morphological characteristics, immunophenotypes, and molecular detection results of lymph node biopsies from three AOSD patients. Results Case 1: lymph node biopsy tissue showed significant lymphoid follicular hyperplasia, accompanied by parafollicular hyperplasia; the germinal centers exhibited a starry-sky phenomenon, with no obvious histiocyte proliferation foci, plasma cells, or neutrophils; immunohistochemical staining showed that CD3 and CD5 T lymphocyte were positive in the paracortical area, CD20 and CD79α markers showed that B lymphocytes were mainly located in the follicular area, CD21 follicular dendritic cells and CD68 histiocytes were positive. Case 2: lymph node puncture tissue showed paracortical hyperplasia, a decrease in the number of follicles, and a reduction of follicular volume; there were no obvious histiocyte proliferation foci, plasma cells, or neutrophils; immunohistochemical staining showed positive CD3, CD5 T lymphocytes in the paracortical area, and CD20, CD79α B lymphocytes in the follicular region. Case 3: lymph node puncture tissue showed partial preservation of the normal lymph node structure, the paracortical area was diffusely proliferated, and the histiocyte hyperplasia was patchy with partial necrosis, and obvious nuclear debris, scattered plasma cells and eosinophils can be seen and no obvious neutrophil infiltration in the necrotic area; immunohistochemical staining of case 3 showed that CD21 and CD23 follicular dendritic cells were positive, and Bcl-2, Bcl-6, CD3, CD5, CD20, CD79α, and multiple myeloma protein 1 (MUM1) were positively expressed in some lymphocytes; the Ki-67 proliferation index was high, approximately 70%; a few plasma cells were positive for CD138, with individual cells positive for CD1α; CD10 and CyclinD1 were negative; histiocytes were positive for myeloperoxidase (MPO); and EBER was negative for in situ hybridization. The results of TCR gene rearrangement and IG gene rearrangement in the three cases were negative. Conclusion The immunophenotype of AOSD is diversity, and its dignosis depends on the clinical and pathological morphological features and immunophenotype, excluding infectious diseases, malignant tumors and lymphoma, etc.

Objective To investigate the effects of KRAS mutation isoforms on tumor regression grade(TRG)of rectal cancer received neoadjuvant therapy.Methods The clinicopathologic data of patients with locally advanced and metastatic rectal cancer(stage Ⅲ-Ⅳ)who underwent radical tumor resection after neoadjuvant therapy were collected.The correlations between the mutated subtypes of KRAS and TRG as well as the clinicopathological features were analyzed.Results A total of 95 patients were enrolled,including 55 patients with poor tumor regression.The incidences of G12V mutation in exon 2 and A146 mutation in exon 4 of the KRAS gene were higher in the group with poor tumor regression than those in the significant tumor regression group(P＜0.05).In patients with G12D mutation of KRAS gene,the histological grade of tumor in poor tumor regression was higher than that in significant tumor regression group(P=0.027).In patients with poor tumor regression,the levels of CD8+,PD-1+T-lymphocyte infiltration were higher in G12D mutation subgroup than those in G12V mutation and G13D mutation subgroups(P＜0.05).Conclusions KRAS G12V mutation and A146 mutation suggest poor neoadjuvant therapy effect for rectal cancer;for patients with KRAS G12D mutation and poor tumor regression,the potential beneficiary for immunotherapy would be screened by detecting CD8+and PD-1+T-lymphocyte infiltration.

Objective To explore the expression and clinical significance of Yes-associated protein 1(YAP1)in esophageal squamous cell carcinoma.Methods Immunohistochemical method was used to detect YAP1 expression in 439 cases of esophageal squamous cell carcinoma.The differences of YAP1 expression and clinical parameters were analyzed between YAP1 positive group and YAP1 negative group.Kaplan-Meier curve was used to analyze the influence of YAP1 expression on survival of patients.Results The positive rate of YAP1 in esophageal squamous cell carcinoma was 30.52% .The tumor invasion was deeper in YAP1 positive group(P＜0.001).Kaplan-Meier survival analysis showed that YAP1 positive patients had longer disease-free survival(DFS)and overall survival(OS)among patients surviving longer than 30 months(P＜0.05).The multivariate Cox regression analysis showed that the invasion depth of tumor was an independent factor affecting DFS(HR=1.371,95% CI 0.993-1.894,P=0.035)and OS(HR=1.489,95% CI 1.066-2.080,P=0.020).Conclusions YAP1 has a certain percentage of positive rate in esophageal squamous cell carcinoma;for patients with survival longer than 30 months,YAP1 positive indicates a better prognosis.