Radiologic Imaging of Scalp Lesions

Scalp lesions present significant diagnostic challenges due to their similar appearances, making accurate radiological assessment crucial in lowering mortality and morbidity rates.
Understanding the scalp's anatomy, which includes five distinct layers-skin, dense connective tissue, epicranial aponeurosis, loose connective tissue, and pericranium-enables precise lesion localization. The vast majority of scalp abnormalities (93–98%) are benign, with trichilemmal cysts being the most common, followed by epidermal and dermal cysts, lipomas, nevi, and sebaceous cysts. Although less frequent, malignant scalp tumors such as squamous cell carcinoma, basal cell carcinoma, lymphoma, metastases and malignant melanoma also occur and pose significant health risks.
Radiological imaging, particularly CT and MRI, plays a vital role in differentiating between benign and malignant lesions. Some characteristic imaging features of specific benign lesions, such as calcifications in trichilemmal cysts, fat density in lipomas, diffusion restriction in epidermoid cysts, and the typical locations of dermoid cysts with well-defined, non-invasive imaging features, aid radiologists in accurate diagnosis. On the contrary, although an accurate diagnosis of malignant tumors cannot be reached by radiological imaging alone, aggressive characteristics like bone erosion, destruction, and infiltration into surrounding tissues should predominantly raise suspicion of malignancy. Proper radiological evaluation and familiarity with the imaging features of these lesions are essential for accurate diagnosis and effective treatment planning, whether surgical or nonsurgical.