金澤 丈治

Mucosa-associated lymphoid tissue (MALT) lymphoma commonly arises from chronic inflammation or autoimmune diseases, such as Sjögren syndrome (SjS). Although rare, amyloid deposition in MALT lymphoma has been reported. We present a rare case of parotid gland MALT lymphoma in a 49-year-old woman, in whom preoperative diagnosis was challenging due to atypical imaging findings resulting from amyloid deposits. MRI showed T2-hypointense and T1-iso- to slightly hyperintense masses in the left parotid gland and right sublingual gland, with predominant marginal contrast enhancement and no significant diffusion restriction. Additionally, atrophy and fatty replacement of the parenchyma were noted in bilateral parotid glands, suggesting SjS. Left superficial parotidectomy was performed and pathological findings confirmed MALT lymphoma with extensive amyloid deposition. Histopathological findings of the resected parotid gland parenchyma also suggested SjS. MALT lymphoma should be considered in the differential diagnosis of multiple salivary gland masses in patients with suspected SjS. If MRI reveals atypical imaging findings for malignant lymphoma, particularly T2-hypointensity with no significant diffusion restriction, the possibility of amyloid deposition in MALT lymphoma should be considered.

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.

Maxillary angiosarcoma, an aggressive tumor derived from vascular endothelial cells, is very rare. Recently, antivascular endothelial growth factor (VEGF) therapies have attracted considerable attention. We describe the clinical course of a patient with maxillary angiosarcoma and discuss the expression of VEGF signaling molecules assessed via immunohistological analysis. An 81-year-old man presented with an aggressive tumor in the left maxillary sinus. Biopsy revealed atypical nuclear cell proliferation, and the tumor was suspected to be a sarcoma. The maxillary malignancy was treated using a multidisciplinary approach with a combination of surgery, radiotherapy, and regional chemotherapy. Examination of the specimen obtained in the first surgery revealed maxillary angiosarcoma, found to be positive for CD31, while negative for CD34, D2-40, and factor Ⅷ. Although no pathological residual tumor was observed after the planned wide surgery, cervical lymph node and distant metastases occurred. The patient died 24 months after the first surgery. Staining revealed VEGF receptor (VEGFR) 1, VEGFR2, phosphorylated Ak strain transforming, mitogen-activated protein kinase, and signal transducer and activator of transcription 3 positivity. Although our findings do not indicate that anti-VEGF therapy is beneficial for treating maxillary angiosarcomas, we found that VEGFR signaling pathways were activated in maxillary angiosarcomas similar to angiosarcomas originating at other sites. Herein, we report a case of maxillary angiosarcoma, focused on VEGFR and signaling pathway activation. To our knowledge, this is the first report to describe VEGFR system immunostaining findings in maxillary angiosarcoma.