45. Nodular melanoma
Staining: HE
Organ: Skin
Description:
Like the name implies the tumor forms a nodule. The tumor cells are highly atypical, bordering on anaplastic. Some of the tumor cells contain melanin.
Tumor cells are present in the epidermis as well.
Diagnosis: Nodular melanoma
Causes:
- Sun exposure
Theory:
The presence of tumor cells in the epidermis is essential to establish the diagnosis of primary melanoma. If there were no tumor cells there the lesion could have been a melanoma metastasis rather than the primary tumor.