Papillary thyroid carcinoma with aggressive fused follicular and solid growth pattern: A unique histological subtype with high-grade malignancy?

Papillary thyroid carcinoma (PTC) is usually indolent; however, some rare subtypes of PTCs, such as columnar cell and hobnail subtypes, carry poor prognosis as an intermediate malignancy between differentiated carcinoma and anaplastic carcinoma. We present the case of a 56-year-old Japanese woman having PTC with aggressive behavior showing characteristic histological features of a predominantly fused follicular and focally solid (FFS) pattern. The fused follicular pattern is cribriform-like without intermingled vessels. This PTC with FFS pattern included frequent mitotic figures, necrosis, lymphovascular invasion, and metastases with high clinical stage. The tumor cells were broadly positive for antibodies to TTF-1, PAX8, and bcl-2, and negative for cyclin D1. Ki-67 labeling index was approximately 10%, and there was occasional positivity of p53. Targeted next generation sequencing analysis only detected a NRAS mutation (Q61K); there was no mutation and no translocation of other genes including BRAF and RET/PTC. To our knowledge, this is first report that PTC shows aggressive FFS growth pattern. The tumor is possibly included in the new category of differentiated high-grade thyroid carcinoma in the World Health Organization 2022 classification, or in a novel subtype of PTC owing to its characteristic histological feature and intermediate malignancy between differentiated carcinoma and anaplastic carcinoma.

A Case of Primary Systemic Amyloidosis Involving the Sinonasal Tract.

We present a case of primary systemic amyloidosis diagnosed by endoscopic sinus surgery. A 75-year-old woman had blurred vision in her left eye; computed tomography and magnetic resonance imaging showed shadows of the bilateral paranasal sinuses. Endoscopic sinus surgery was performed, and amyloidosis was diagnosed by histopathology. She had previously been diagnosed with amyloidosis of the stomach, and therefore, she was diagnosed with primary systemic amyloidosis. A systemic workup for additional amyloid deposits revealed no evidence of other diseases. The patient remained under follow-up without further treatment, as no further amyloid deposition or progression of the lesions was seen. Amyloidosis is a rare condition characterized by the deposition of abnormal protein filaments in the extracellular tissue. Generally, systemic amyloidosis does not involve the head and neck region, and the presence of amyloid in the nasal and paranasal sinus mucosa is more likely to be indicative of a localized process. However, in our patient, the lesions were located in both the sinonasal tract and the stomach, indicating systemic amyloidosis. To our knowledge, there have been no previous reports of systemic amyloidosis involving the sinonasal tract, and therefore, we consider this case to be extremely rare.

Ambient fine and coarse particles in Japan affect nasal and bronchial epithelial cells differently and elicit varying immune response.

Ambient particulate matter (PM) epidemiologically exacerbates respiratory and immune health, including allergic rhinitis (AR) and bronchial asthma (BA). Although fine and coarse particles can affect respiratory tract, the differences in their effects on the upper and lower respiratory tract and immune system, their underlying mechanism, and the components responsible for the adverse health effects have not been yet completely elucidated. In this study, ambient fine and coarse particles were collected at three different locations in Japan by cyclone technique. Both particles collected at all locations decreased the viability of nasal epithelial cells and antigen presenting cells (APCs), increased the production of IL-6, IL-8, and IL-1ß from bronchial epithelial cells and APCs, and induced expression of dendritic and epithelial cell (DEC) 205 on APCs. Differences in inflammatory responses, but not in cytotoxicity, were shown between both particles, and among three locations. Some components such as Ti, Co, Zn, Pb, As, OC (organic carbon) and EC (elemental carbon) showed significant correlations to inflammatory responses or cytotoxicity. These results suggest that ambient fine and coarse particles differently affect nasal and bronchial epithelial cells and immune response, which may depend on particles size diameter, chemical composition and source related particles types.

Synergic effects of 9,10-phenanthrenequinone and cadmium on pro-inflammatory responses in airway epithelial cells.

We investigated the synergic effects of components of particulate matter with aerodynamic diameters ≤2.5µm (PM2.5) on airway inflammation. Co-exposure to cadmium (Cd) and 9,10-phenanthrenequinone (9,10-PQ) additively/synergistically increased pro-inflammatory responses in airway epithelial cells, whereas co-exposure to Cd and phenanthrene resulted in no acceleration. These results suggest that the combination of metal and a quinone derivative can contribute to the exacerbation of respiratory diseases by PM2.5.