Why is immunohistochemistry necessary for compound nevi?
Dec 01, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
Immunohistochemical staining of a compound nevus may be performed to confirm the diagnostic characteristics, differentiate between benign and malignant lesions, assess cellular proliferative activity, and evaluate the depth of invasion. The cellular morphology of a compound nevus can sometimes resemble other pigmented lesions; immunohistochemical detection of specific protein expression helps clearly distinguish compound nevi from other subtypes of melanocytic nevi or similar conditions such as seborrheic keratosis, thereby avoiding misdiagnosis.
In general, immunohistochemical staining of compound nevi may be performed to confirm the diagnostic characteristics, differentiate between benign and malignant lesions, assess cellular proliferative activity, evaluate the depth of infiltration, and assist in formulating treatment plans. The details are as follows:
1. Confirming diagnostic characteristics: The cellular morphology of compound nevi can sometimes resemble other pigmented skin lesions. Immunohistochemistry detects the expression of specific proteins, clearly distinguishing compound nevi from other subtypes of melanocytic nevi or similar conditions such as seborrheic keratosis, thus avoiding misdiagnosis.
2. Differentiating benign from malignant: Some compound nevi may exhibit atypical hyperplasia, making it difficult to determine malignancy based on routine histopathological examination alone. Immunohistochemistry helps accurately distinguish the benign nature of compound nevi from malignant conditions such as melanoma by detecting the expression of malignant markers.
3. Assessing cellular proliferative activity: Immunohistochemistry can detect markers related to cell proliferation, providing insight into the growth rate of nevus cells. Abnormally increased proliferative activity may indicate potential malignant transformation, guiding decisions for close monitoring or intervention.
4. Evaluating depth of infiltration: For suspicious compound nevi, immunohistochemistry can clearly reveal the distribution of cells across different layers of the skin, determining whether the lesion has breached normal tissue boundaries and infiltrated deeper skin layers, thereby helping assess the extent of disease progression.
5. Assisting in treatment planning: Once immunohistochemistry clarifies the nature, benignity or malignancy, and severity of the compound nevus, physicians can develop more precise treatment strategies—such as deciding whether benign nevi require only observation or whether suspicious lesions need wider excision.
If a compound nevus shows changes such as increasing size, uneven color, or indistinct borders, prompt medical evaluation is recommended. Patients should follow medical advice when undergoing immunohistochemical testing and promptly discuss results with their doctor to determine appropriate follow-up management and avoid delays in care.
