45. Nodular melanoma

Staining: HE

Overview

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

Tumour cells containing melanin

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.

Severe atypia, or even anaplasia

Tumour cells in the epidermis