Benign neoplasms include hepatocellular adenoma, hepatic hemangioma and focal nodular hyperplasia. Darkly pigmented lesions can be challenging to distinguish from nodular melanomas. This technique demonstrates hepatic parenchyma and it's accurate for detecting nodular carcinomas and infiltrating lesions. A goitre may be classified either as nodular or diffuse. Polypoid melanoma is a virulent variant of nodular melanoma. The lesion may be rough or nodular in texture. The lesions may be flat (macules), raised (papules), or solid elevated areas (nodular). There are three distinct types of vulvar melanoma&colon; superficial spreading, nodular, and acral lentigous melanoma. It can also be seen in nodular basal-cell carcinomas. Calcitonin assay is used in identifying patients with nodular thyroid diseases. Macroscopically, liver cancer appears as a nodular or infiltrative tumor. Diffuse and nodular are similar in behavior. The diffuse type of episcleritis may be less painful than the nodular type. That is longer than diffuse type and almost as long as nodular (almost 7 yrs). Heterotopias are classed in two groups&colon; "nodular" and "diffuse".