Different degrees of inflammatory reaction and/or ulcer formation can be seen. Typical lesions are hawk-eye-like (surrounded by halo) cytomegalovirus inclusion bodies, which are more common in vascular endothelial cells and interstitial cells at the bottom of ulcers, especially in the presence of macrophages. Infiltration around blood vessels and occasionally within epithelial cells. This inclusion body can exist in the cytoplasm or nucleus, and can be seen in cytology smears and HE staining. Immunohistochemistry is sometimes required to aid diagnosis.

Immunohistochemistry: CMV positive

Characteristics: acute inflammation and ulcer, with exfoliated cells in the inflammatory exudate. Typical lesions are intranuclear inclusions that make the nuclei appear ground glass. Multinucleated giant cells may be seen. The presence of large monocyte (CD68) aggregates with coiled nuclei near inflammatory epithelium is an important diagnostic clue

HSV positive, CD68 staining showing large mononuclear cells with coiled nuclei

Four major characteristics: granulation tissue formation, significant active inflammation, muscle layer involvement, and no other source of infection (special staining, immunohistochemistry, and culture are all negative)

Immunohistochemistry: HIV positive

The squamous epithelium has convex or papillary protrusions, the epithelial feet are extended, thickened or pseudoepithelioma-like hyperplasia, the surface cells often have parakeratosis, and the basal layer cells proliferate. There are varying degrees of lymphocyte and plasma cell infiltration in the lamina propria, and scattered or groups of koilocytes can be seen in the spinous layer.

Bacterial invasion of the esophageal mucosa layer or deep layer confirmed by histopathology, and excluding the simultaneous presence of fungal, viral or neoplastic esophageal diseases and no history of esophageal surgery in the past

There may be no inflammatory reaction, but there may be a large number of bacteria "buried" in the squamous epithelium. Severe lesions may manifest as significant purulent inflammation and/or extensive tissue necrosis

Candida albicans or Candida tropicalis infection

Different degrees of acute inflammation, from mild inflammation to abscess, ulcer, necrosis, and even pseudomembrane formation. Candida pseudohyphae and spores can be seen in necrosis and exudation, which are easily seen in brush cytology specimens but not in HE sections. Candida pseudohyphae and spores often exist in parakeratosis or pseudomembranes Pseudohyphae are the basis for diagnosis

Special staining: PAS and hexaamine silver staining positive

esophageal aspergillosis

A large number of hyphae branching at 45° can be seen under the microscope. Aspergillus easily invades blood vessels, causing thrombosis and/or coagulative necrosis, and is often accompanied by other microbial infections, but the inflammatory reaction is often mild.

Special staining: PAS, PAS-D and hexaammonium silver staining positive