Case Report: A complete pathologic response in pancreatic cancer with squamous cell differentiation.

Primary pancreatic malignancies are mostly composed of the adenocarcinoma histological subtype. However, squamous cell carcinoma (SCC) accounts for approximately 0.5%-1% of all malignant pancreatic cancers. Because of the rarity of SCC of the pancreas, guideline-directed treatment is lacking, treatment response is difficult to access, and treatment options are poorly defined. Here, we report a case of a 65-year-old man diagnosed with pancreatic carcinoma with dominant squamous cell differentiation, who achieved complete pathologic response (CPR) after treatment with gemcitabine, cisplatin, and nab-paclitaxel every 14 days for six cycles and who continues to lead a high quality of life 7 months later. To our knowledge, this is the first case of CPR in a case of SCC of the pancreas. To highlight the ambiguity and the need for further studies, we also performed a narrative review analyzing recent cases and compared them to our case.

Endometrial Adenocarcinoma with Discordant Microsatellite Stability Status Treated with First-Line Pembrolizumab: A Case Report and Narrative Review.

BACKGROUND Microsatellite instability (MSI) is a hallmark of specific cancers and can be diagnosed using both tissue- and liquid-based approaches. When these tissue- and liquid-based approaches give differing results, they are known as discordant or being at variance. MSI-H tumors are well-researched candidates for treatment with programmed cell death protein 1 (PD-1) inhibitor-based immunotherapy, but the efficacy of immunotherapy in MSI-H discordant endometrial cancer, especially as first-line therapy, is not yet well documented in the literature. CASE REPORT A 67-year-old woman presented with a retroperitoneal mass positive for recurrent adenocarcinoma of endometrial origin. Her stage I endometrial adenocarcinoma 7 years ago demonstrated microsatellite stable (MSS) by immunohistochemical (IHC) stain and indeterminant due to insufficient tissue by Caris Next-Generation Sequencing (NGS). She then presented with a retroperitoneal mass that was MSI-H on IHC stain and Caris NGS, as well as MSI high on liquid biopsy @Guardant360 (@G360). The patient proceeded with pembrolizumab treatment 1 year ago and has sustained a complete clinical response at the time of writing. CONCLUSIONS Our case provides further evidence for the need to retest the microsatellite stability of metastatic sites, especially after a long disease-free survival. Here, we providing a literature review of case reports and a review of studies outlining discordance of testing modalities. Our case also highlights the importance of considering the use of immunotherapy as a first-line agent in patients who may have a poor ECOG performance status, as it can significantly improve their quality of life and reduce the number of adverse effects compared to chemotherapy.

Drug-Induced Thrombocytopenia Due to Nintedanib during Treatment of Idiopathic Pulmonary Fibrosis.

Nintedanib is a tyrosine kinase inhibitor that was approved for the treatment of patients with idiopathic pulmonary fibrosis in 2014. The most common side effect of Nintedanib is diarrhea, and thrombocytopenia is a rare side effect of Nintedanib. The exact mechanism is unknown, and the literature lacks case reports of this phenomenon. Here, we report the case of a patient who developed thrombocytopenia 12 weeks after starting treatment with Nintedanib. The patient underwent an extensive work up for infectious, hematological, autoimmune, and neoplastic diseases. The patient's thrombocytopenia resolved following cessation of Nintedanib. This case is significant as it reports a rare side effect that might have detrimental consequences if not recognized and treated timely. Additionally, the onset of thrombocytopenia was delayed, 3 months after the initiation of Nintedanib. We also highlight the various literature regarding drug-induced thrombocytopenia and explore the necessary work-up needed to exclude other potential diagnoses. We hope to advocate for multidisciplinary teams to be aware of patients with pulmonary fibrosis on Nintedanib so that this adverse effect can be recognized promptly.