Objective:To investigate the cytopathological features of thyroid tumor with DICER1 mutation.Methods:A retrospective study on the preoperative cell smear was conducted on thyroid tumors with DICER1 gene mutations detected by Sanger sequencing in the Department of Pathology Shanghai Sixth People′s Hospital affiliated to Shanghai Jiaotong University School of Medicine from May 2022 to November 2024.Results:Totally 163 cases with histological features indicating DICER1 mutation related thyroid tumor underwent Sanger sequencing. Fifteen cases were confirmed to harbor DICER1 mutation (15/163,9.2%). Fourteen of 15 patients were female, and only 1 was male; average age 42(31,47) years. Eight cases presented with D1709 hotspot mutation (8/15) and 7 cases with the E1813 hotspot mutation (7/15) and there was no statistical significant difference between mutation rate of different hotspot ( F=0.620， P=0.438). All specimens were stained with hematoxylin-eosin staining. A moderate number of cells were observed for all cases, predominantly with macrofollicular pattern and rare small papillae. The cell nuclei were mainly uniform, small, round and dark, slightly enlarged or medium-sized. Several cases could also present RAS-like nuclear features: 3 cases showed visible nuclear grooves. According to the expert consensus on the cytopathological diagnosis of thyroid fine needle aspiration (version 2023),the cytopathological diagnostic categories were: Ⅱ, 6 cases; Ⅲ, 2 cases; Ⅳ, 6 cases; and Ⅴ, 1 case. Postoperative histological diagnoses included follicular thyroid carcinoma in 2 cases, high-grade differentiated thyroid carcinoma in 1 case, follicular thyroid adenoma in 3 cases, follicular thyroid tumor of undetermined malignant potential in 4 case, and thyroid follicular nodular disease in 5 cases. Conclusions:The morphological features of DICER1-mutated thyroid tumors are predominant macrofollicles, with uniformly small round and dark nuclei. It is difficult to identify typically diagnostic atrophic follicles on cell smear, leading to a preoperative diagnosis of benign non-neoplastic or indeterminate category. Therefore, it is necessary to carefully observe the macro-follicles and small round dark nuclear features, which is necessary to suggest a genetic test of DICER1 gene and to confirm the diagnosis before surgery.

Objective:To analyze the cytological, histological, immunohistochemical, and molecular pathological features of hyalinizing trabecular tumor (HTT).Methods:Clinical and pathological data of the HTT cases diagnosed at Shanghai Sixth People′s Hospital affiliated to Shanghai Jiao Tong University School of Medicine between 2020 and 2024 were collected and analyzed. HE staining, special staining, immunohistochemical staining, and next-generation sequencing were performed on all cases.Results:Among the 10 HTT patients, 4 were male and 6 were female. The age at onset ranged from 29 to 85 years, with a median age of 49 (35,61) years. The maximum tumor diameter ranged from 0.3 to 5.3 cm. Cytologically, the smears were hypercellular and showed tumor cells arranged in nested clusters with visible basement membrane-like material. The nuclei were oval with finely granular chromatin, and nuclear pseudoinclusions were readily identifiable. Histologically, the tumors were well demarcated. The tumor cells were arranged in a paraganglioma-like pattern, exhibiting typical nuclear features of papillary thyroid carcinoma and psammoma bodies. Yellow bodies were observed in the cytoplasm. The stroma was rich in hyalinized material, which was periodic acid-Schiff stain (PAS)-positive. Immunohistochemically, the tumor cells showed diffuse expression of TTF-1 and focal expression of thyroglobulin. Aberrant immunoreaction with Ki-67 was present in the cytoplasm and membrane of the tumor cells. Molecular testing was performed on 8 cases. The PAX8-GLIS3 gene fusion was detected in 7 cases. Among these fusion-positive cases, 4 exhibited additional genetic abnormalities: one concurrent TSHR point mutation (p.D617H); one concurrent HRAS point mutation (p.Q61R); one concurrent LRP1B point mutation (p.S1752L), SUGCT point mutation (p.K137), and TERT point mutation (p.P785L); one concurrent MTOR mutation (7528+27A>T) and FLT3 mutation (p.E77K). The key initiating factors for thyroid carcinoma, including the BRAF V600E mutation and RET rearrangements, were absent in all cases tested.Conclusions:Cellular pleomorphism, yellow bodies and basement membrane-like material constitute important cytological and histological features for the differential diagnosis of HTT. Immunophenotypically, thyroglobulin may show focal expression, while Ki-67 is typically localized in the tumor cell membrane and cytoplasm. This study also demonstrates that PAX8-GLIS3 fusion is a characteristic molecular abnormality in HTT, although cases with wild type of GLIS gene may also present. Although rare, HTT may harbor point mutations in HRAS and TSHR, and other uncommon genetic alterations.

Objective:To investigate the cytopathological features of thyroid tumor with DICER1 mutation.Methods:A retrospective study on the preoperative cell smear was conducted on thyroid tumors with DICER1 gene mutations detected by Sanger sequencing in the Department of Pathology Shanghai Sixth People′s Hospital affiliated to Shanghai Jiaotong University School of Medicine from May 2022 to November 2024.Results:Totally 163 cases with histological features indicating DICER1 mutation related thyroid tumor underwent Sanger sequencing. Fifteen cases were confirmed to harbor DICER1 mutation (15/163,9.2%). Fourteen of 15 patients were female, and only 1 was male; average age 42(31,47) years. Eight cases presented with D1709 hotspot mutation (8/15) and 7 cases with the E1813 hotspot mutation (7/15) and there was no statistical significant difference between mutation rate of different hotspot ( F=0.620， P=0.438). All specimens were stained with hematoxylin-eosin staining. A moderate number of cells were observed for all cases, predominantly with macrofollicular pattern and rare small papillae. The cell nuclei were mainly uniform, small, round and dark, slightly enlarged or medium-sized. Several cases could also present RAS-like nuclear features: 3 cases showed visible nuclear grooves. According to the expert consensus on the cytopathological diagnosis of thyroid fine needle aspiration (version 2023),the cytopathological diagnostic categories were: Ⅱ, 6 cases; Ⅲ, 2 cases; Ⅳ, 6 cases; and Ⅴ, 1 case. Postoperative histological diagnoses included follicular thyroid carcinoma in 2 cases, high-grade differentiated thyroid carcinoma in 1 case, follicular thyroid adenoma in 3 cases, follicular thyroid tumor of undetermined malignant potential in 4 case, and thyroid follicular nodular disease in 5 cases. Conclusions:The morphological features of DICER1-mutated thyroid tumors are predominant macrofollicles, with uniformly small round and dark nuclei. It is difficult to identify typically diagnostic atrophic follicles on cell smear, leading to a preoperative diagnosis of benign non-neoplastic or indeterminate category. Therefore, it is necessary to carefully observe the macro-follicles and small round dark nuclear features, which is necessary to suggest a genetic test of DICER1 gene and to confirm the diagnosis before surgery.

Objective:To analyze the cytological, histological, immunohistochemical, and molecular pathological features of hyalinizing trabecular tumor (HTT).Methods:Clinical and pathological data of the HTT cases diagnosed at Shanghai Sixth People′s Hospital affiliated to Shanghai Jiao Tong University School of Medicine between 2020 and 2024 were collected and analyzed. HE staining, special staining, immunohistochemical staining, and next-generation sequencing were performed on all cases.Results:Among the 10 HTT patients, 4 were male and 6 were female. The age at onset ranged from 29 to 85 years, with a median age of 49 (35,61) years. The maximum tumor diameter ranged from 0.3 to 5.3 cm. Cytologically, the smears were hypercellular and showed tumor cells arranged in nested clusters with visible basement membrane-like material. The nuclei were oval with finely granular chromatin, and nuclear pseudoinclusions were readily identifiable. Histologically, the tumors were well demarcated. The tumor cells were arranged in a paraganglioma-like pattern, exhibiting typical nuclear features of papillary thyroid carcinoma and psammoma bodies. Yellow bodies were observed in the cytoplasm. The stroma was rich in hyalinized material, which was periodic acid-Schiff stain (PAS)-positive. Immunohistochemically, the tumor cells showed diffuse expression of TTF-1 and focal expression of thyroglobulin. Aberrant immunoreaction with Ki-67 was present in the cytoplasm and membrane of the tumor cells. Molecular testing was performed on 8 cases. The PAX8-GLIS3 gene fusion was detected in 7 cases. Among these fusion-positive cases, 4 exhibited additional genetic abnormalities: one concurrent TSHR point mutation (p.D617H); one concurrent HRAS point mutation (p.Q61R); one concurrent LRP1B point mutation (p.S1752L), SUGCT point mutation (p.K137), and TERT point mutation (p.P785L); one concurrent MTOR mutation (7528+27A>T) and FLT3 mutation (p.E77K). The key initiating factors for thyroid carcinoma, including the BRAF V600E mutation and RET rearrangements, were absent in all cases tested.Conclusions:Cellular pleomorphism, yellow bodies and basement membrane-like material constitute important cytological and histological features for the differential diagnosis of HTT. Immunophenotypically, thyroglobulin may show focal expression, while Ki-67 is typically localized in the tumor cell membrane and cytoplasm. This study also demonstrates that PAX8-GLIS3 fusion is a characteristic molecular abnormality in HTT, although cases with wild type of GLIS gene may also present. Although rare, HTT may harbor point mutations in HRAS and TSHR, and other uncommon genetic alterations.

Activation of the heart normally begins in the sinoatrial node (SAN). Electrical impulses spontaneously released by SAN pacemaker cells (SANPCs) trigger the contraction of the heart. However, the cellular nature of SANPCs remains controversial. Here, we report that SANPCs exhibit glutamatergic neuron-like properties. By comparing the single-cell transcriptome of SANPCs with that of cells from primary visual cortex in mouse, we found that SANPCs co-clustered with cortical neurons. Tissue and cellular imaging confirmed that SANPCs contained key elements of glutamatergic neurotransmitter system, expressing genes encoding glutamate synthesis pathway (Gls), ionotropic and metabotropic glutamate receptors (Grina, Gria3, Grm1 and Grm5), and glutamate transporters (Slc17a7). SANPCs highly expressed cell markers of glutamatergic neurons (Snap25 and Slc17a7), whereas Gad1, a marker of GABAergic neurons, was negative. Functional studies revealed that inhibition of glutamate receptors or transporters reduced spontaneous pacing frequency of isolated SAN tissues and spontaneous Ca

Serum anti-M2 mitochondrial antibody (AMA-M2) was screened with immune colloidal gold technique in 6 008 individuals aged over 60 years who underwent health check-up in Xuhui District of Shanghai,the positive samples were retested with ELISA method.The results showed that 1.31％ (79/6 008) individuals were AMA-M2 positive; the positive rate was 0.82％ (18/2 186) in males and 1.60％ (61/3 822) in females.Eleven subjects with positive AMA-M2 underwent further investigation,8 cases were diagnosed as primary biliary cirrhosis (PBC) and the remaining 3 were highly suspected as PBC.All 11 individuals were abnormal in biochemical tests of liver function and/or clinical symptoms.