Mixed Neuroendocrine Carcinoma and Hepatocellular Carcinoma: A Case Report and Literature Review

Mixed Neuroendocrine Non-Neuroendocrine Tumor (MINEN) of the Liver: Report of Two Cases and Review of the Literature

OBJECTIVE

To highlight two cases mixed neuroendocrine non-neuroendocrine tumors (MINEN) of the liver and to review the literature till date. To present two cases of MINEN of the liver diagnosed in our centre with clinical & diagnostic workup, the treatment modalities, and follow up. Extensive review of the literature and compilation of the presentation and treatment modalities used in those cases.

CASE REPORTS

Thirty-three cases of MINEN of the liver have been reported till date including ours. Our cases presented as incidental masses in liver during workup for other symptoms. AFP levels were normal in both cases but PIVKA (Protein induced by vitamin K absence) levels were increased. Resection was done in one of the cases while the other patient had to undergo transplantation. A diagnosis of MINEN was made on H&E, and confirmed on IHC. One patient was unfit for systemic chemotherapy whereas the other patient received cisplastin and etoposide based chemotherapy. Both patients developed metastasis on follow up but are still alive after 12-15 months.

CONCLUSION

MINEN is an uncommon tumor of the liver with a poor prognosis as shown by the few studies available. Recurrence and distant metastases are often described even after complete resection and the course is fatal. The role of adjuvant chemotherapy following surgical resection is not fully elucidated. Mean survival in the cases reported ranged from 1 month to 33 months. However, no significant differences were seen in the clinicopathologic profile of the cases described so far. Further multiinstitutional studies and follow up will help to further characterize this subtype for appropriate treatment.

Enhancer landscape of lung neuroendocrine tumors reveals regulatory and developmental signatures with potential theranostic implications

Well-differentiated low-grade lung neuroendocrine tumors (lung carcinoids or LNETs) are histopathologically classified as typical and atypical LNETs, but each subtype is still heterogeneous at both the molecular level and its clinical manifestation. Here, we report genome-wide profiles of primary LNETs' cis-regulatory elements by H3K27ac ChIP-seq with matching RNA-seq profiles. Analysis of these regulatory landscapes revealed three regulatory subtypes, independent of the typical/atypical classification. We identified unique differentiation signals that delineate each subtype. The "proneuronal" subtype emerges under the influence of ASCL1, SOX4, and TCF4 transcription factors, embodying a pronounced proneuronal signature. The "luminal-like" subtype is characterized by gain of acetylation at markers of luminal cells and GATA2 activation and loss of LRP5 and OTP. The "HNF+" subtype is characterized by a robust enhancer landscape driven by HNF1A, HNF4A, and FOXA3, with notable acetylation and expression of FGF signaling genes, especially FGFR3 and FGFR4, pivotal components of the FGF pathway. Our findings not only deepen the understanding of LNETs' regulatory and developmental diversity but also spotlight the HNF+ subtype's reliance on FGFR signaling. We demonstrate that targeting this pathway with FGF inhibitors curtails tumor growth both in vitro and in xenograft models, unveiling a potential vulnerability and paving the way for targeted therapies. Overall, our work provides an important resource for studying LNETs to reveal regulatory networks, differentiation signals, and therapeutically relevant dependencies.

Mixed Hepatocellular-Neuroendocrine Carcinoma: A Case Report and Literature Review

Mixed hepatocellular-neuroendocrine carcinoma (HCC-NEC) is a rare entity with a poor prognosis. We report a case of a 44-yearold Tunisian man who was admitted for diffuse abdominal pain. Body computed tomography showed multinodular hepatomegaly. Pathologic findings concluded to HCC-NEC. Clinicians should be aware about this entity. Further collection of case reports is needed to standardize the optimal treatment.

Primary Hepatic Neuroendocrine Carcinoma with Thrombocytopenia Due to Diffuse Bone Marrow and Splenic Infiltration: An Autopsy Case

An 82-year-old man with fever and back pain was referred to our hospital and was thus found to be thrombocytopenic. A bone marrow biopsy revealed the diffuse infiltration of poorly differentiated neuroendocrine carcinoma (NEC). Computed tomography revealed a large hepatic mass. Considering the risk of bleeding due to thrombocytopenia, a needle biopsy was not performed. The patient rapidly deteriorated and died 10 days after presentation. An autopsy confirmed the diagnosis of primary hepatic NEC, with diffuse metastasis to the spleen, bone marrow, and systemic lymph nodes. This is an extremely rare case of NEC presenting with thrombocytopenia due to extensive bone marrow and splenic infiltration.

Developing a competing risk nomogram that predicts the survival of patients with a primary hepatic neuroendocrine tumor

Primary hepatic neuroendocrine tumor (PHNET) is rare liver cancer and related prognostic factors are unclear. The aim of this study was to analyze the prognostic risk factors of patients with PHNETs and establish an assessment model for prognosis. The clinical information of 539 patients with PHNETs who met the criteria for inclusion was extracted from the Surveillance, Epidemiology, and End Results (SEER) database. These patients were randomly assigned to the training (269 cases) and validation sets (270 cases). Prognostic factors in patients with PHNETs were screened using the Cox proportional regression model and Fine–Gray competing risk model. Based on the training set analysis using the Fine–Gray competing risk model, a nomogram was constructed to predict cumulative probabilities for PHNET-specific death. The performance of the nomogram was measured by using receiver operating characteristic curves, the concordance index (C-index), calibration curves, and decision curve analysis (DCA). No differences in clinical baseline characteristics between the training and validation sets were observed, and the Fine–Gray analysis showed that surgery and more than one primary malignancy were associated with a low cumulative probability of PHNET-specific death. The training set nomograms were well-calibrated and had good discriminative ability, and good agreement between predicted and observed survival was observed. Patients with PHNETs with a high-risk score had a significantly increased risk of PHNET-specific death and non-PHNET death. Surgical treatment and the number of primary malignancies were found to be independent protective factors for PHNETs. The competing risk nomogram has high accuracy in predicting disease-specific survival (DSS) for patients with PHNETs, which may help clinicians to develop individualized treatment strategies.

Mixed neuroendocrine–nonneuroendocrine neoplasms of the gastrointestinal system: An update

Mixed neuroendocrine-nonneuroendocrine neoplasms (MiNENs) of the digestive tract are a rare heterogeneous group of tumors that present many challenges in terms of diagnosis and treatment. Over the years, the diagnostic criteria, classification, and clinical behavior of these tumors have been the subjects of ongoing debate, and the various changes in their nomenclature have strengthened the challenges associated with MiNENs. This review is performed to provide an understanding of the key factors involved in the evolution of the designation of these tumors as MiNEN, highlight the current diagnostic criteria, summarize the latest data on pathogenesis and provide information on available treatments. Moreover, this work seeks to increase the awareness about these rare neoplasms by presenting the clinicopathological features and prognostic factors that play important roles in their behavior and discussing their different regions of origin in the gastrointestinal system (GIS). Currently, the MiNEN category also includes tumors in the GIS with a nonneuroendocrine component and epithelial tumors other than adenocarcinoma, depending on the organ of origin. Diagnosis is based on the presence of both morphological components in more than 30% of the tumor. However, this value needs to be reconfirmed with further studies and may be a limiting factor in the diagnosis of MiNEN by biopsy. Furthermore, available clinicopathological data suggest that the inclusion of amphicrine tumors in the definition of MiNEN is not supportive and warrants further investigation. The diagnosis of these tumors is not solely based on immunohistochemical findings. They are not hybrid tumors and both components can act independently; thus, careful grading of each component separately is required. In addition to parameters such as the metastatic state of the tumor at the time of diagnosis and the feasibility of surgical resection, the aggressive potential of both components has paramount importance in the choice of treatment. Regardless of the organ of origin within the GIS, almost MiNENs are tumors with poor prognosis and are frequently encountered in the elderly and men. They are most frequently reported in the colorectum, where data from molecular studies indicate a monoclonal origin; however, further studies are required to provide additional support for this origin.