Thyroid follicular adenoma with accumulation of collagen type IV in a common marmoset (Callithrix jacchus)

A spontaneous middle ear adenocarcinoma characterized by abundant eosinophilic matrix in a young male Crl:CD(SD) rat

A mass was detected in the right tympanic cavity of a 15-week-old male Crl:CD(SD) rat. Histological examination revealed papillary or tubular proliferations of epithelial cells including ciliated cells that produce mucus and have an abundant eosinophilic matrix. The malignancy of this tumor was revealed by its destructive proliferation, cellular polymorphism, and high proliferative activity. The tumor was diagnosed as a middle ear adenocarcinoma due to its location and histological characteristics. This is the first report of a middle ear adenocarcinoma in rats and the first middle ear tumor accompanied by eosinophilic matrix observed in either humans or animals. The eosinophilic matrix was positive for periodic acid-Schiff and periodic acid-silver methenamine stains and for laminin and collagen Type IV, immunohistochemically, but negative for Congo red, which suggested that this matrix was a basement membrane substance.

Spectroscopic identification of benign (follicular adenoma) and cancerous lesions (follicular thyroid carcinoma) in thyroid tissues

Thyroid follicular nodules are quite common in the population, however only a small proportion is malignant. Thyroid cancer differs from adenoma by features of cellular atypia, angioinvasiveness and possibility of metastasis via blood vessels mainly in the lungs and bones. Pathomorphological examination of the postoperative material plays a significant role in the diagnosis of cystic thyroid lesions. De facto, there is no possibility to determine with certainty whether the lesion is benign or malignant before surgery, therefore new methods are being sought to meet clinical needs. The study aimed to investigate if Fourier-transform infrared spectroscopy (FTIR) spectroscopy and Raman spectroscopy combined with multidimensional analysis can be a useful tool in distinguishing between thyroid adenomas and carcinomas. The obtained results indicate quantitative and qualitative alterations within proteins and fats derived from patients' tissues samples. Raman spectroscopy additionally shows significant changes in the amount of tissue collagen due to the pathogenic process. In the spectra of the second FTIR derivative, shifts of vibrations corresponding to the β-sheet and α-helix structure are observed towards the lower rates of wave numbers in the case of neoplastic tissues. Using the leave-one-out cross-validation, sensitivity and specificity calculated with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) clearly shows the possibility to distinguish between pathologically changed and normal thyroid tissue as well as differentiate follicular thyroid adenoma (FTA) from widely invasive follicular thyroid carcinoma (WI-FTC) tissues.