A typical acantholytic cell of phemphigus as seen in a Tzanck smear is called a 'Tzanck cell' ( see image below). It is a rounded keratinocyte with a hypertrophic or dysmorphic nucleus, hazy or absent nucleoli, increased nuclear to cytoplasmic ratio due to the loss of normal intercellular cohesion and abundant eosinophilic to basophilic cytoplasm. The staining is more intensely basophilic near the cell membrane ('mourning edge') because of cytoplasmic condensation at the periphery, resulting in a perinuclear halo.

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