What is the Difference Between Melanocytes and Nevus Cells

The key difference between melanocytes and nevus cells is that melanocytes are cells typically found in the skin and eyes, while nevus cells are a variant of melanocytes typically found in the dermo-epidermal junction in the interface between the epidermal and the dermal layers of the skin.

Both melanocytes and nevus cells can produce the pigment melanin. Nevus cells are a variant of melanocytes. However, nevus cells are larger than typical melanocytes, and they are mainly found in the dermo-epidermal junction in the interface between the epidermal and the dermal layers of the skin.

CONTENTS

1. Overview and Key Difference
2. What are Melanocytes 
3. What are Nevus Cells
4. Similarities – Melanocytes and Nevus Cells
5. Melanocytes vs. Nevus Cells in Tabular Form
6. Summary – Melanocytes vs Nevus Cells

What are Melanocytes?

Melanocytes are neural crest-derived cells. Neural crest cells are a temporary group of cells that originate from the embryonic ectoderm germ layer. They produce the pigment melanin. Melanocytes are normally located in the bottom layer of the epidermis of the skin, the middle layer of the eye known as the uvea, the inner ear, the vaginal epithelium, the meninges,  bones, and the heart.

Melanin is a darker pigment. It is usually responsible for skin colour. After synthesizing, melanin is stored in a special organelle called melanosome. Later, melanosomes can be transported to nearby keratinocytes to induce pigmentation. Moreover, darker skin tones have more melanosomes than lighter skin tones. When it comes to their function, melanin serves as a protection agent against UV radiation. In addition to their role as UV radical scavengers or UV protection agents, melanocytes are also a part of the immune system. Therefore, they are considered to be immune cells. Furthermore, there are different diseases that occur due to low levels of melanin content in the body, such as vitiligo, oculocutaneous albinism, and Chédiak–Higashi syndrome. These diseases often have a familial genetic influence.

What are Nevus Cells?

Nevus cells are a variant of the melanocytes. Nevus cells are larger than normal melanocytes. These cells are usually found in the dermo-epidermal junction in the interface between the epidermal and the dermal layers of the skin. Nevus cells can also be found in lymph nodes and the thymus. Nevus cells do not have dendrites, but they have abundant cytoplasm with coarse granules.

Dermal nevus cells can be further classified into; type A, type B, and type C. Moreover, type A dermal nerve cells mature into type B dermal nerve cells, and type B dermal nerve cells mature into type C dermal nerve cells through a process involving downward migration. Furthermore, nevus cells are also the primary component of a melanocytic nevus which is a benign skin lesion due to a local proliferation of pigment cells.

What are the Similarities Between Melanocytes and Nevus Cells?

• Both melanocytes and nevus cells can produce the pigment melanin.
• Nevus cells are a variant of melanocytes.
• Both cells can be found in the skin.
• They are also associated with diseases.

What is the Difference Between Melanocytes and Nevus Cells?

Melanocytes are cells producing and containing the pigment called melanin, typically found in the skin and eyes, while nevus cells are a variant of melanocytes typically found in the dermo-epidermal junction in the interface between the epidermal and the dermal layers of the skin. Thus, this is the key difference between melanocytes and nevus cells. Furthermore, melanocytes have dendrites, while nevus cells have no dendrites.

The infographic below presents the differences between melanocytes and nevus cells in tabular form for side-by-side comparison.

Summary – Melanocytes vs. Nevus Cells

Melanocytes and nevus cells can both produce melanin. Nevus cells are known as modified melanocytes. Melanocytes in the epidermis of the skin are evenly dispersed as single units. On the other hand, nevus cells cluster as nests within the lower epidermis and dermis in the skin. Moreover, melanocytes can also be found in the eyes, the inner ear, the vaginal epithelium, the meninges, bones, and the heart, while nevus cells can be found in lymph nodes and thymus other than the skin. So, this summarizes the difference between melanocytes and nevus cells.

Reference:

1. Cichorek, Mirosława, et al. “Skin Melanocytes: Biology and Development.” Postepy Dermatologii i Alergologii.
2.“Nevus Cell – An Overview.” ScienceDirect.

Image Courtesy:

1. “Blausen 0632 Melanocyte” By Blausen.com staff (2014). “Medical Gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) Commons Wikimedia
2. “Skin Tumors-171” By LWozniak&KWZielinski – Own work (CC BY-SA 3.0) via Commons Wikimedia