Single-cell profiling of response to neoadjuvant chemo-immunotherapy in surgically resectable esophageal squamous cell carcinoma.

BACKGROUND: The efficacy of neoadjuvant chemo-immunotherapy (NAT) in esophageal squamous cell carcinoma (ESCC) is challenged by the intricate interplay within the tumor microenvironment (TME). Unveiling the immune landscape of ESCC in the context of NAT could shed light on heterogeneity and optimize therapeutic strategies for patients. METHODS: We analyzed single cells from 22 baseline and 24 post-NAT treatment samples of stage II/III ESCC patients to explore the association between the immune landscape and pathological response to neoadjuvant anti-PD-1 combination therapy, including pathological complete response (pCR), major pathological response (MPR), and incomplete pathological response (IPR). RESULTS: Single-cell profiling identified 14 major cell subsets of cancer, immune, and stromal cells. Trajectory analysis unveiled an interesting link between cancer cell differentiation and pathological response to NAT. ESCC tumors enriched with less differentiated cancer cells exhibited a potentially favorable pathological response to NAT, while tumors enriched with clusters of more differentiated cancer cells may resist treatment. Deconvolution of transcriptomes in pre-treatment tumors identified gene signatures in response to NAT contributed by specific immune cell populations. Upregulated genes associated with better pathological responses in CD8 + effector T cells primarily involved interferon-gamma (IFNγ) signaling, neutrophil degranulation, and negative regulation of the T cell apoptotic process, whereas downregulated genes were dominated by those in the immune response-activating cell surface receptor signaling pathway. Natural killer cells in pre-treatment tumors from pCR patients showed a similar upregulation of gene expression in response to IFNγ but a downregulation of genes in the neutrophil-mediated immunity pathways. A decreased cellular contexture of regulatory T cells in ESCC TME indicated a potentially favorable pathological response to NAT. Cell-cell communication analysis revealed extensive interactions between CCL5 and its receptor CCR5 in various immune cells of baseline pCR tumors. Immune checkpoint interaction pairs, including CTLA4-CD86, TIGIT-PVR, LGALS9-HAVCR2, and TNFSF4-TNFRSF4, might serve as additional therapeutic targets for ICI therapy in ESCC. CONCLUSIONS: This pioneering study unveiled an intriguing association between cancer cell differentiation and pathological response in esophageal cancer patients, revealing distinct subgroups of tumors for which neoadjuvant chemo-immunotherapy might be effective. We also delineated the immune landscape of ESCC tumors in the context of clinical response to NAT, which provides clinical insights for better understanding how patients respond to the treatment and further identifying novel therapeutic targets for ESCC patients in the future.

Primary pulmonary hyalinizing clear cell carcinoma with pseudopapillary structures and abundant cysts filled with mucus.

Pulmonary hyalinizing clear cell carcinoma (HCCC) is a new and rare form of lung salivary gland tumor. Only twenty-two cases have been reported in the literature to date. Furthermore, their clinicopathological features have not been fully characterized. In this paper, we describe the clinicopathological characteristics, immunohistochemical features, and molecular genetic changes in two HCCC cases. We also simultaneously reviewed related literature on similar cases reported. Of the two cases, one was of a 58-year-old man with a 4.3 cm lung tumor, which was the largest among all previously reported cases. The tumor showed an infiltrative growth pattern and perineural and vascular invasion microscopically. Moreover, nuclear grooves, high mitotic figures, and comedo necrosis were observed in addition to classic morphological features. More importantly, rare pseudopapillary structures were observed. The second case was of a 60-year-old woman in whom the tumor was mainly composed of multiple cysts filled with mucus. The remaining focal solid areas of the tumor comprised clear and acidophilic cells embedded in the hyalinizing stroma. Immunohistochemical analysis revealed that the tumor cells of both cases were positive for CK5/6, p40, and p63 expression, but negative for napsin A, TTF-1, and SOX10 expression. The HCCC diagnosis in both cases was validated by fluorescence in-situ hybridization (FISH) examination, which showed Ewing sarcoma breakpoint region 1-activating transcription factor 1 (EWSR1-ATF1) gene fusion. Primary pulmonary HCCC is a rare lung tumor originating from the bronchial mucosa, and its histological features may vary, such as rare pseudopapillary structures and abundant cysts. Thus, the diagnosis should be a combined analysis of histopathological characteristics with immunophenotype and molecular examination, including EWSR1-ATF1 gene fusion detection.

Primary collision tumors of the sellar region: Experience from a single center.

Collision tumors are extremely rare in the sellar region, and their features have not been fully characterized. Here, we report our single-center experience in the diagnosis and management of these tumors, focusing primarily on their clinicopathological features. We first performed a retrospective study of pathological reports from patients who had undergone surgery for pituitary adenoma (PA) or craniopharyngioma (CP) at our hospital. Next, to identify collision tumors, patients with a second pathological diagnosis-such as Rathke's cleft cyst (RCC), gangliocytoma (GC), meningioma, or atypical teratoid/rhabdoid tumor (AT/RT)-were considered. Finally, the clinicopathological characteristics of these tumors were reviewed and analyzed. The results demonstrated that eleven of 2359 PA or CP cases (0.47 %) were found to exhibit sellar collision tumors; the patient cohort had a median age of 52 years (23-71) and was predominantly female (63.6 %, 7/11). In details, of the 2092 cases of PA, 10 were diagnosed with concurrent lesions (seven of RCC and one each of CP, meningioma, and GC). Of the 267 CP cases, a single patient presented with associated AT/RT. To our knowledge, this is the first reported adult case of this subtype. Notably, the preoperative CT and/or MRI of each patient revealed solely PA or CP. The endoscopic endonasal approach was the preferred surgery. In conclusion, the sellar collision tumors occur with low incidence, and the primary subtype is PA and RCC. Their definitive diagnosis depends primarily on pathological findings.

Hepatocellular carcinoma metastasis to the gingival soft tissues: A case report and review of the literature.

Metastases to the gingival soft tissues are rare in hepatocellular carcinoma (HCC). To the best of our knowledge, only 13 cases have been reported in English literature to date. The present study described the case of a 43-year-old Chinese man who was admitted to Tangdu Hospital (Xi'an, China) due to the presence of a gingival tumor that was initially diagnosed as granulation tissue by a dental surgeon. Examination of the patient's medical history revealed that a solid mass, measuring 1.5 cm in diameter, was identified in the right lobe of the liver 2 years prior to presentation at the current hospital; however, no biopsy was performed. Thus, the tumor was resected and histological examination resulted in an initial diagnosis of atypical squamous cell carcinoma. However, the histopathological characteristics, immunohistochemical features and serum α-fetoprotein expression levels supported a diagnosis of metastatic HCC. In conclusion, the present case study highlights the difficulties in diagnosing metastatic HCC without a history of primary HCC, and the importance of excluding a diagnosis of metastatic tumor when a lesion is identified in the gingival. Furthermore, it was determined that a final diagnosis of gingival metastasis of HCC predominantly depends on pathological characteristics and immunohistochemical features.