​Dermatology - Nodular Melanoma

​Dermatology - Nodular Melanoma 
Nodular melanoma (NM) is the second most prevalent type of melanoma in individuals with light skin. It primarily affects middle-aged individuals and tends to develop on parts of the body that receive less sun exposure. Initially, this tumor undergoes vertical development, specifically affecting the dermis. For unexplained reasons, NM is significantly more prevalent among individuals of Japanese heritage, occurring eight times more frequently than superficial spreading melanoma.

Nodular melanoma (NM) can originate from a preexisting nevus, but it is more frequently developed from normal skin without any prior conditions. It typically progresses over a few months and is often identified by the patient as a new growth resembling a mole.
Abnormalities
The lesion is a consistently raised, thick plaque or a protruding, polypoid, or dome-shaped growth, typically exhibiting smooth and regular boundaries. The color pattern typically lacks variation, with the lesion appearing consistently blue or blue-black. In rare cases, it may be mildly pigmented or completely nonpigmented (amelanotic melanoma). Nodular melanoma (NM) is a kind of primary melanoma that develops quickly (between a few months to 2 years) from normal skin or a melanocytic nevus. It grows vertically without an adjacent epidermal component, which is always seen in lentigo maligna melanoma and superficial spreading melanoma. Initial lesions have a size ranging from 1 to 3 cm, however they can significantly increase in size if not discovered.

The diagnosis is made through a clinical assessment, which is then confirmed with dermoscopy and/or biopsy. Performing a complete excisional biopsy with minimal margins is the most effective approach. If the biopsy results are positive, it is necessary to perform a reexcision. Incisional or punch biopsy is a suitable alternative when it is not possible to do a complete excisional biopsy or when the lesion is large and would require considerable surgery to remove it entirely. The differential diagnosis for blue/black lesions includes hemangioma (with a long history), pyogenic granuloma, and pigmented basal cell cancer. Any newly formed nodule like a blueberry should be surgically removed or, if it is of significant size, subjected to a biopsy.


The treatment involves surgically removing tissue down to the fascia. To guarantee proper treatment for lesions that are less than 1 mm thick, it is important to have a margin of 1 cm from the edges of the lesion. Biopsy of lymph nodes should only be performed if the nodes can be felt or detected through touch. For lesions that are larger than 1 mm in thickness, it is important to have a 2-cm margin and do a biopsy of the sentinel lymph nodes. Proceed with excision followed by immediate closure or repair using skin grafts. Perform lymphadenectomy exclusively for nodal basins that contain hidden tumor cells or if the nodes are clinically detectable and show signs of potential tumor presence. Adjuvant therapy should be considered in cases where there is a danger of recurrence, such as when there are positive regional lymph nodes or the cancer is in an advanced stage.