In pathology

Pathology

Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....

, the Grocott's methenamine silver stain, abbreviated GMS, is a popular staining method in histology

Histology

Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...

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It is used widely as a screen for fungal organisms. Particularly useful in staining carbohydrates.

It can be used to identify the yeast-like fungus Pneumocystis jiroveci which causes a form of pneumonia

Pneumonia

Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...

called Pneumocystis Pneumonia (PCP) or Pneumocystosis.

The cell walls of these organisms are outlined by the brown to black stain.