Merkel cell carcinoma is a rare and aggressive disease. The disease gets initiated from the skin commonly due to the infection of polyomavirus and spreads rapidly to other body tissues. Merkel cells are believed to act as mechanoreceptors.
How Aggressive Is Merkel Cell Carcinoma?
Merkel cells are found below the epidermis. These cells can sense the touch stimulus. This is because these cells are situated very close to nerve endings. These cells contain some chemicals that may be effective acts as hormones1. These cells are devoid of any coverings thus are sensitive to even a low-pressure sensation and even a very low pressure has a long-term sensitive effect because of their non-covering characteristic. Merkel cells are first discovered by Friedrich Merkel and are named after its discoverer. These cells were first identified in the paws of rats2.
The cells are most densely located in the area where the touch sensation is highly acute. These areas include lips, face, and fingertips. Studies indicate that these cells contain hormones and thus are also known as neuroendocrine cells. However, why they have hormone-like chemicals largely remains unknown.
The origin of Merkel cell is a controversial issue. While animal studies indicate that they have been originated from the neural crest, human studies show that they are of epidermal origin.
Merkel cell carcinoma is caused due to the abnormal overgrowth of Merkel cells. Merkel cell carcinoma is also known as primary cutaneous neuroendocrine carcinoma. It is considered a rare disease with high spreading potential. Old age people with fair skin color are at high risk of developing Merkel cell carcinoma. In most cases, the causative agent is Polyomavirus, which is responsible for almost 80% of the total cases. Weak immune system and prolong exposure to sunlight are other causes that may lead to Merkel cell carcinoma.
What Is The Function Of A Merkel Cell?
Also known as Merkel Ranvier cells, the Merkel cells are mechanoreceptors which can sense even the low level of pressure. The mechanism is attributed because of their nearness to the dick like nerve endings commonly known as the tactile meniscus. The detailed structure of Merkel cells reveals that they have spines, and dendrites, loosely arrange skeleton and dense-core granules3.
Progression Of Merkel Cell Carcinoma
Merkel cell carcinoma is highly aggressive and spreads within the body at a rapid pace. The Merkel cell carcinoma is a progressive disease and progresses through various stages. The stages of Merkel cell carcinoma is decided based on the following criterion:
- Size and thickness of the tumor.
- Determine the location of the tumor near the lymph node and how much nodes involved in this tumor
- Spreading of cancer cells beyond lymph nodes
- Affected organ and tissues
Staging is required to evaluate the extent of the spread of disease. Staging is an important parameter for creating an effective treatment strategy and also to analyze the prognosis of the condition. Disease, when diagnosed in advanced stages, requires aggressive treatment and the prognosis is poor.
Merkel cell carcinoma has the following stages:
Stage 1: It is the primary stage of the tumor. In this stage, the tumor size is less than or equal to 2 cm. Cancer does not spread to lymph nodes at this stage.
Stage 2: In this stage, the size of the tumor is increased compared to the primary stage and the lymph node is also involved in this stage.
Stage 3: In this stage, the regional lymph nodes are involved, and the disease progresses to transit metastasis stage.
Stage 4: In this stage, the tumor metastasized in outside the lymph node and also spread in the other part or organ of the body4.
Various stages are depicted to show the severity and spread of Merkel cell carcinoma. In the initial stage, the condition is limited to the skin while in other stages Merkel cell carcinoma spreads to other tissues initiating with invading lymph nodes. Merkel cells sense the touch and pressure on the skin.
- What is Merkel Cell Carcinoma (MCC), Causes, Symptoms, Treatment, Complications, Prevention
- How Dangerous Is Merkel Cell Carcinoma & Is It Contagious?
- How Do You Stop Merkel Cell Carcinoma From Spreading?
- How Does Merkel Cell Carcinoma Affect The Body & What Triggers It?
- Is There A Surgery For Merkel Cell Carcinoma?
- Life Expectancy Of Someone With Merkel Cell Carcinoma