Parakeratosis is a term pathologists use to describe an abnormal change involving cells called keratinocytes, found on the surface of the skin and other tissues lined by squamous cells. Normally, keratinocytes form a protective barrier and lose their nucleus (the part of the cell that holds genetic material) as they move towards the skin’s surface. However, in parakeratosis, these surface cells keep their nuclei. This change is considered abnormal because healthy surface cells typically have no nuclei.
What types of conditions are associated with parakeratosis?
Parakeratosis can be seen in several skin conditions, especially inflammation or abnormal cell growth. Common examples include:
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Inflammatory skin conditions such as psoriasis (a chronic condition causing red, scaly patches) and eczema (also called spongiotic dermatitis), which can cause itchy and inflamed skin.
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Precancerous conditions, including squamous cell carcinoma in situ (an early form of skin cancer limited to the top layer of the skin).
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Skin cancers such as squamous cell carcinoma, a type of cancer that originates from squamous cells, typically due to sun exposure.
How do pathologists test for parakeratosis?
Pathologists identify parakeratosis by closely examining skin or tissue samples under the microscope. To highlight the cells, tissue samples are typically stained with hematoxylin and eosin or H&E. If parakeratosis is present, pathologists see keratinocytes at the surface of the skin that still have visible nuclei, indicating an abnormal maturation process.
What does parakeratosis mean in a pathology report?
Parakeratosis itself is not a diagnosis; it’s a descriptive term pathologists use to explain what they see under the microscope. Because parakeratosis can be found in many different conditions—ranging from common inflammation (such as psoriasis) to precancerous and cancerous changes—pathologists use additional features seen in the tissue sample to determine the underlying cause. Your doctor will consider these findings, along with your symptoms and medical history, to make an accurate diagnosis and choose the appropriate treatment.
