Moles: Symptoms, Types, Causes and Treatment

Moles are a common feature of human skin, often appearing as small, pigmented spots. While most moles are harmless, some can signal health concerns, including the risk of skin cancer. In addition to skin moles, the term "mole" also refers to unique medical conditions, such as hydatidiform moles, which are related to pregnancy and have very different implications. This article provides a comprehensive exploration of both cutaneous (skin) moles and hydatidiform moles, examining their symptoms, types, causes, and treatment options. Whether you’re navigating changes in your skin or seeking insight into rare pregnancy-related conditions, understanding the science and clinical approach to moles can empower you to make informed health decisions.

Symptoms of Moles

Moles can present with a variety of symptoms, depending on their type and location. Skin moles are usually benign and present as dark spots or raised bumps, while hydatidiform moles—an entirely different phenomenon—are linked to abnormal pregnancy symptoms. Recognizing the key signs associated with each kind is crucial for timely intervention and peace of mind.

Symptom	Description	Relevance	Source
Pigmentation	Brown or black spots on the skin	Common in skin moles	2
Change	Growth, color, or border changes	Possible malignancy	2
Bleeding	Unusual bleeding from a mole	Warning sign	2
Vaginal Bleeding	Bleeding during pregnancy	Hydatidiform mole	3 4
No Embryo	Pregnancy without embryo	Hydatidiform mole	4

Table 1: Key Symptoms

Skin Mole Symptoms

For most people, skin moles (melanocytic naevi) appear as small, brown, or black spots. They are typically round or oval, with smooth edges and uniform color. Most moles remain unchanged for years. However, changes in a mole’s size, shape, or color can be a sign of malignant transformation (melanoma) and warrant medical attention. Other warning signs include:

• Itching or tenderness
• Bleeding or oozing
• Irregular borders or multiple colors

These symptoms are especially relevant if the mole appears suddenly or looks different from others on your body (sometimes called the “ugly duckling” sign) 2.

Hydatidiform Mole Symptoms

Unlike skin moles, hydatidiform moles occur in pregnancy and are unrelated to the skin. Symptoms include:

• Abnormal vaginal bleeding, usually in the first trimester
• Rapid uterine growth
• Absence of fetal heartbeat
• Severe nausea or vomiting
• In some cases, passage of grape-like cysts from the vagina

A hallmark is the absence of an embryo or fetus during ultrasound, despite a positive pregnancy test. These findings are crucial for prompt diagnosis and management 3 4.

Types of Moles

Moles are not a one-size-fits-all phenomenon. Understanding the various types—both on the skin and in reproductive health—can help clarify their risks and guide monitoring and treatment.

Type	Features	Significance	Source
Globular	Raised, early-life, BRAF mutation	May rarely become melanoma	2
Reticular	Flat, net-like, BRAF/NRAS mutation	Can be associated with melanoma	2
PG Reticular	Growing, non-malignant	Benign	2
Complete Hydatidiform	No embryo, all paternal chromosomes	High risk of complications	3 4

Table 2: Types of Moles

Skin Mole Types

Dermatologists classify skin moles based on their appearance under a dermatoscope and their cellular makeup:

• Globular naevi: These moles are typically raised and appear early in life. They often carry mutations in the BRAF gene and are considered benign, though rarely, they can transform into melanoma.
• Reticular naevi: Flat and net-like, these moles appear in adulthood and may carry mutations in BRAF or NRAS genes. They can occasionally be linked to melanoma that arises in an area where a visible mole was not previously detected.
• Reticular with Peripheral Globules (PG): These are growing moles but are not malignant. They also harbor BRAF mutations but are not associated with immediate risk. 2

Hydatidiform Mole Types

Hydatidiform moles are a type of gestational trophoblastic disease. The most significant types are:

• Complete hydatidiform mole: Contains only paternal chromosomes, no embryo or fetus, and often arises due to a genetic error during fertilization. These have a higher risk of progressing to malignant conditions.
• Partial hydatidiform mole: (Not detailed extensively in the sources) Usually contains both maternal and paternal chromosomes, a malformed fetus, and a lower risk of malignancy 3 4.

Causes of Moles

The origins of moles are rooted in genetics, cell biology, and, in the case of hydatidiform moles, reproductive errors. Decoding these causes is crucial for understanding both the benign and harmful potential of moles.

Cause	Mechanism	Associated Mole Type	Source
BRAF/NRAS Mutations	MAPK pathway activation	Skin moles & melanoma	2
Androgenesis	Only paternal chromosomes fertilize	Hydatidiform moles	3 4
Meiotic Error	Maternal chromosomes lost	Hydatidiform moles	4

Table 3: Causes of Moles

Genetic Mutations in Skin Moles

Most skin moles are the result of localized proliferations of melanocytes (pigment-producing cells), often triggered by mutations in specific genes:

• BRAF mutations: Common in globular and peripheral globule naevi, leading to abnormal activation of the MAPK pathway, which promotes cell growth.
• NRAS mutations: Found especially in reticular naevi, also activating the MAPK pathway, which is implicated both in benign mole formation and in melanoma 2.

The presence of these mutations even in benign moles underscores the importance of regular monitoring, as any change could indicate progression towards malignancy.

Hydatidiform Moles: Androgenesis and Meiotic Errors

Hydatidiform moles occur when there is a fundamental error in conception. In complete moles, only paternal chromosomes are present, a result of "androgenesis"—the fertilization of an egg that has lost its maternal DNA. This can happen if the egg’s chromosomes are expelled before or during fertilization, and the sperm’s genetic material duplicates, resulting in a diploid set of chromosomes all from the father 3 4.

Research has identified specific genetic defects in women with recurrent hydatidiform moles, particularly in genes involved in the formation of double-strand breaks during meiosis (MEI1, TOP6BL/C11orf80, and REC114). These defects can cause the egg to lose all its chromosomes, setting the stage for androgenesis and mole formation 4.

Treatment of Moles

Treating moles depends on their type, location, and risk profile. While most skin moles require minimal intervention, hydatidiform moles demand prompt and specialized care. Understanding available therapies can alleviate anxiety and improve outcomes.

Treatment	Approach or Method	Used For	Source
Observation	Monitoring for changes	Benign skin moles	2
Excision	Surgical removal	Suspicious skin moles	2
Uterine Evacuation	Removal via suction or surgery	Hydatidiform mole	6
Hysterectomy	Surgical removal of uterus	Older patients, high risk	6
Chemotherapy	Post-mole malignant sequelae	Malignant GTD	6

Table 4: Treatments for Moles

Skin Mole Management

• Observation: Most harmless moles can be left alone but should be monitored for any changes in size, color, or shape.
• Surgical Excision: If a mole shows atypical features or is suspected of being melanoma, it is surgically removed and sent for pathological analysis. Early removal is crucial if cancer is suspected 2.

Hydatidiform Mole Treatment

Hydatidiform moles are managed differently from skin moles:

• Uterine evacuation: The primary treatment is the prompt removal of the mole from the uterus, typically via suction curettage or, less commonly, by abdominal surgery (hysterotomy). This is essential to prevent complications and possible progression to malignancy.
• Hysterectomy: For women over 40 or those at higher risk, hysterectomy (removal of the uterus) may be considered as definitive primary treatment 6.
• Chemotherapy: If there is evidence of persistent disease or malignant transformation (such as choriocarcinoma), chemotherapy is employed. Follow-up is crucial to monitor for recurrence or complications 6.

Conclusion

Moles are a multifaceted topic, ranging from common skin growths to rare and complex pregnancy-related conditions. Understanding their symptoms, types, causes, and treatment options is essential for early detection and proper management.

Key takeaways:

• Symptoms: Most skin moles are benign, but changes in appearance or unusual symptoms warrant medical attention. Hydatidiform moles present with abnormal pregnancy symptoms.
• Types: Skin moles vary by appearance and genetic mutations. Hydatidiform moles are classified as complete or partial, with very different implications.
• Causes: Skin moles are typically driven by BRAF or NRAS mutations, while hydatidiform moles result from genetic and meiotic errors leading to androgenesis.
• Treatment: Skin moles often require simple observation or excision, while hydatidiform moles require urgent uterine evacuation and, sometimes, additional therapy.

By staying informed about the signs and science behind moles—whether on your skin or related to pregnancy—you can better protect your health and seek timely care when needed.