福嶋 敬宜

The tumor microenvironment is highly heterogeneous and consists of neoplastic cells and diverse stromal components, including fibroblasts, endothelial cells, pericytes, immune cells, local and bone marrow-derived stromal stem and progenitor cells, and the surrounding extracellular matrix. Although the significance of p16 and p53 has been reported in various tumor types, their involvement in the stromal cells of oral squamous cell carcinoma (OSCC) remains unclear. We performed immunohistochemical analyses of p16 and p53 expression in OSCC samples, Of the 116 samples, 74 showed p16-positive stromal cells, and 33 showed p53-positive stromal cells. Both p16 and p53 positivity were associated with an increased histological grade, lymphovascular invasion, an immature stromal pattern with abundant amorphous extracellular matrix material, infiltrative invasion patterns (Yamamoto Kohama classification-4C and 4D), and poor prognosis. Multivariate analyses identified p16 and p53 positivity in the stroma as independent prognostic factors for overall survival (P = 0.032 and P = 0.020, respectively); moreover, stromal p16 positivity correlated with stromal p53 positivity. These findings indicated that p16 and p53 stroma positivity may regulate OSCC tumor aggressiveness.

A 50-year-old man was diagnosed with type 1 autoimmune pancreatitis (AIP) following endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and a histopathological examination. After six months of untreated follow-up, the serum IgG4 level decreased, and the diffuse pancreatic enlargement improved; however, a pancreatic head mass became apparent. EUS-FNA of this mass revealed pancreatic ductal adenocarcinoma (PDAC) with IgG4-positive plasma cells. In addition, the resected specimen revealed PDAC, without any features of AIP. After pancreatoduodenectomy, AIP did not recur. The development of AIP in this case could be related to paraneoplastic syndrome.

INTRODUCTION: Moderately differentiated neuroendocrine tumors of the larynx are rare malignant tumors that arise from the submucosa of the larynx, for which surgery is the first-line treatment. PRESENTATION OF CASE: We report a case of moderately differentiated neuroendocrine tumor of the larynx, in which the patient, a 74-year-old man, experienced long-term palliation but an unfortunate outcome of death owing to metastasis. Laryngeal endoscopic examination revealed an elevated submucosal lesion on the laryngeal surface of the epiglottis. Computed tomography and magnetic resonance imaging showed a tumor-like lesion demonstrating a contrasting effect in the submucosa of the epiglottis. A biopsy revealed a moderately differentiated neuroendocrine tumor (formerly called an atypical carcinoid), and a horizontal partial laryngectomy was performed. The patient had a good postoperative course; however, three years and ten months after surgery, he experienced recurrence in the upper gastrointestinal tract and carcinoid syndrome and died four years and three months after the surgery. DISCUSSION: The prognosis of laryngeal neuroendocrine tumors remains poor. In this case, local control was possible without irradiation because the resection margins were negative on pathological examination. This case report has been reported in line with the SCARE Criteria. CONCLUSION: Long-term follow-up of this type of tumor is necessary, as distant metastasis is likely to affect prognosis. In addition to surgery, effective adjuvant therapies, including molecular targeted therapies, should be established.