Frequent expression of PD-L1 in lymphocyte-rich hepatocellular carcinoma: A report of 4 cases

Clinicopathological Characteristics of Neutrophil-Rich Hepatocellular Carcinoma: An Uncommon Subtype of Primary Liver Cancer

Introduction. Neutrophil-rich hepatocellular carcinoma (HCC) is an extremely uncommon subtype of HCC with an overall incidence of <1%. Neutrophil-rich HCC shows poor cellular differentiation and sarcomatoid transformation in most patients. There is prominent neutrophilic inflammatory cell infiltration in the tumor. These tumors are associated with poor prognosis, high rate of recurrence, and metastasis. Methods. Herein, we investigated 4 patients with neutrophil-rich HCC reported at our center. Clinical, radiological, and pathological findings were reviewed. Immunophenotypic characterization of the tumors were done. Granulocyte colony-stimulating factor (G-CSF), programmed cell death ligand 1 (PD-L1), and mismatch repair immunostains were performed in all 4 tumors. Results. We report 4 neutrophil-rich HCCs in 3 male patients and one female patient with an age range of 43 to 64 years. Three underwent living donor liver transplantation and one underwent right hepatectomy. Tumor measured 0.5 cm to 12 cm in maximum dimension. Histologically, tumors demonstrated moderate to marked cellular pleomorphism. Spindle cell transformation was noted in 3 tumors. Three tumors showed vascular invasion, and one tumor showed bile duct invasion. Immunopositivity for Hep Par-1, arginase-1, and glypican-3 was present in all tumors. Tumors also expressed stemness markers including KRT19 and EpCAM. Cytoplasmic positivity for G-CSF and immunoexpression of PD-L1 was demonstrated. We also report proficient mismatch repair by immunohistochemistry in all tumors. Conclusion. Neutrophil-rich HCC is an aggressive primary liver cancer which demonstrates stemness-related features. Programmed cell death ligand 1 expression in tumor cells suggests distinct immunogenic features and potential role of anti-PD-L1 therapies in inoperable disease.

Granuloma rich hepatocellular carcinoma (GrHCC): Clinicopathologic and genomic characterization

There is limited literature on sarcoid like granuloma (SLG) associated with hepatocellular carcinoma (HCC). Here in, we studied clinicopathological characteristics, and explored the potential significance of SLG in HCC. We termed these tumors as granuloma rich HCC (GrHCC). We reviewed clinicopathologic features in 30 GrHCC tumors that were diagnosed in 21 patients during a period of 68-month at a single institution. The study included 17 males and 4 females, with ages ranging from 43 to 71 years in males and 20 to 69 years in females. Tumor downstaging was done in 4 patients. Tumor sizes ranged from 0.6 to 23 cm, with a mean size of 2.41 cm. Majority of tumors showed well to moderate cellular differentiation. A solitary well-formed epithelioid granuloma sufficed to classify the tumor as GrHCC. The intratumoral granulomas were compact, well-formed, and discrete, consisting of collections of epithelioid histiocytes and multinucleate histiocytic giant cells. Mild lymphocytic inflammation was also noted. Single to several granulomas were identified in the tumor. Size of granuloma ranged from 170 to 650 μm. Only one tumor showed necrotizing granulomas. Genomic analysis of 4 tumors revealed TP53 mutation. Two tumors also exhibited a TERT promoter mutation. All patients were alive till last follow-up, except for one, who died due to septic shock, unrelated to the HCC. This study provides valuable insights into the clinical findings, histopathological features and molecular characteristics of GrHCC.

Clinicopathologic features and tumor immune microenvironment of lymphocyte-rich hepatocellular carcinoma

Lymphocyte-rich hepatocellular carcinoma (LR-HCC) is a rare variant of HCC characterized by pronounced lymphoid infiltration, providing an opportunity to explore the tumor immune microenvironment (TIME) and its potential impact on disease progression and therapy. This study aimed to describe the clinicopathological features and TIME components of LR-HCC to inform more effective treatment strategies. In this study, we present five novel cases of LR-HCC alongside a comprehensive retrospective analysis of 136 previously documented cases. Immunohistochemical evaluation was utilized to systematically assess TIME components and immune checkpoint inhibitor (ICI) targets. Our findings demonstrated a significant predominance of CD3+ T cells over CD20+ B cells (1.5:1, P < 0.001) and a higher frequency of CD8+ cytotoxic T cells compared to Foxp3+ regulatory T cells (2.4:1, P < 0.001), indicating an immune landscape potentially favorable for immunotherapeutic interventions. Programmed cell death ligand 1 (PD-L1) expression was detected in three out of five cases using the VENTANA SP263 assay, suggesting potential responsiveness to ICIs. A pooled analysis of 38 cases showed a 5-year overall survival rate of 73.6 %, which is notably lower than previously reported rates (>90 %), with 29.4 % of patients experiencing postoperative recurrence or lymph node metastasis. Multivariate analysis identified tumor size as an independent predictor of overall survival. These findings emphasize the relevance of TIME characteristics in understanding LR-HCC and point to promising avenues for targeted and immune-based therapies, contributing to the optimization of clinical management for this distinct cancer subtype.

Treatment and prognostic implications of strong PD-L1 expression in primary hepatic sarcomatoid carcinoma

Primary hepatic sarcomatoid carcinoma (HSC) is an extremely rare and aggressive subtype of primary liver cancer. HSC has uncertain pathogenesis and dismal prognosis with overall survival of only 8.3 months. The molecular alterations of HSC are also not well understood. In this study, the authors describe a patient who presented with a large liver mass. The patient underwent complete surgical resection and histological examination demonstrated HSC, infiltrating the stomach. PD-L1 was strongly positive in the tumor cells. The patient was started on anti-PD-L1 immunotherapy postsurgery and is doing well 15 months after surgical resection. Tumor whole exome sequencing revealed genetic alterations in TP53, NF2 and MAGEC3 genes, indicating their potential role in tumor development.

Aggressive Variant of Hepatic Epstein-Barr Virus-Associated Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma with PD-L1 and SSTR2a Expression

An aggressive Epstein-Barr virus (EBV)-associated inflammatory pseudotumor-like follicular dendritic cell (IPT-like FDC) sarcoma is reported in an adult female. The patient developed multifocal recurrence and passed away 13 months after the initial surgical resection. A bright field microscopic examination of the tumor demonstrated a classical growth pattern and the diffuse expression of Programmed death ligand 1 (PD-L1) and somatostatin receptor 2a (SSTR2a).