The pharyngeal arches as seen during embryonic development<unk> s are remnants of embryonic development and result from a failure of obliteration of one of the<unk><unk> s, which are homologous to the structures in fish that develop into gills. Pathology The cyst wall is composed of squamous epithelium (90%), columnar cells with or without cilia, or a mixture of both, with lymphoid infiltrate, often with prominent germinal centers and few subcapsular lymph sinuses. The cyst is typically surrounded by lymphoid tissue that has attenuated or absent overlying epithelium due to inflammatory changes. The cyst may or may not contain granular and keratinaceous cellular debris. Cholesterol crystals may be found in the fluid extracted from a<unk>  cyst.
Branchial cleft cyst
Vascular anomaly
Thyroglossal cyst
Lymphadenopathy
Paradental cyst
Lymphoma
Vocal cord cyst
Thymus