Wahin-Finkeldey giant cells are seen in

In measles, the lymphoid organs typically have marked follicular hyperplasia, large germinal centers, and randomly distributed multinucleated faint cells, called Wahin-Findkeldey cells, which have eosinophilic nuclear and cytoplasmic inclusion bodies. These are pathognomic of measles and are also in the lung and sputum. Giant cells resulting from the fusion of cells -Viral infection Epithelial giant cells, e.g. herpes virus infection Connective tissue, e.g. Wahin-Finkeldey giant cells in measles Ref: Pathologic basis of disease (Robbins and cotran)7th edition, page no.364