Cholesterol crystals may be found in the fluid extracted from a branchial cyst. Diagnosis
The diagnosis of branchial cleft cysts is typically done clinically due to their relatively consistent location in the neck, typically anterior to the sternocleidomastoid muscle. For masses presenting in adulthood, the presumption should be a malignancy until proven otherwise, since carcinomas of the tonsil, tongue base and thyroid may all present as cystic masses of the neck. Unlike a thyroglossal duct cyst, when swallowing, the mass should not move up or down. Types
Four branchial clefts (also called "grooves") form during the development of a human embryo. The first cleft normally develops into the external auditory canal, but the remaining three arches are obliterated and have no persistent structures in normal development. Persistence or abnormal formation of these four clefts can all result in branchial cleft cysts which may or may not drain via sinus tracts. First branchial cleft cysts account for 8% of the sinuses and cysts of the neck. The cysts are usually located in the front or behind the ears, lateral to the facial nerve, parallel to the external auditory canal. Second branchial cleft cysts account for 90 to 95% of the neck cysts. It is located medial to the facial nerve, at the anterior neck, anterior to the sternocleidomastoid muscle, above the hyoid bone. Skin pit can be found in this location. However, if skin pits are found on both sides of the neck, then, branchio-oto-renal syndrome should be ruled out.
Dipylidium caninum, also called the flea tapeworm, double-pored tapeworm, or cucumber tapeworm (in reference to the shape of its cucumber-seed-like proglottids, though these also resemble grains of rice or sesame seeds), is a cyclophyllid cestode that infects organisms afflicted with fleas and canine chewing lice, including dogs, cats, and sometimes human pet-owners, especially children. Adult morphology
The adult worm is about 18 inches (46 cm) long. Gravid proglottids containing the worms microscopic eggs are either passed in the definitive hosts feces or may leave their host spontaneously and are then ingested by microscopic flea larvae (the intermediate hosts) in the surrounding environment. As in all members of family Dipylidiidae, proglottids of the adult worm have genital pores on both sides (hence the name double-pore tapeworm). Each side has a set of male and female reproductive organs. The uterus is paired with 16 to 20 radial branches each. The scolex has a retractable rostellum with four rows of hooks, along with the four suckers that all cyclophyllid cestodes have. Life cycle
The definitive host within this life cycle is primarily canines, and occasionally felines, and in rare cases young children. The intermediate hosts include fleas (Ctenocephalides spp.) and chewing lice. The first stage in the life cycle is when the gravid proglottids are either passed out through faecal matter, or actively crawl out of the anus of the host. The gravid proglottids once out of the definitive host release eggs.