A biopsy shows Tzanck cells. In which ganglion does the causative virus lie dormant?

Tzanck cells (acantholytic multinucleated giant cells) are seen in herpes infections (HSV-1, HSV-2, VZV). HSV-1 (oral herpes) lies dormant in the trigeminal ganglion (Gasserian ganglion). VZV lies in sensory ganglia including trigeminal. Geniculate ganglion houses VZV for herpes zoster oticus (Ramsay Hunt syndrome). Tzanck → HSV → trigeminal.