Subungual Melanoma

There is a notable difference between subungual hematomas and subungual melanoma.

In this article, you will read about the difference in these two topics. You will also review signs/symptoms, treatments, and prognosis, of each. ⁽¹⁾ Many times there is much confusion with the multiple names given to malignant melanoma. Subungual simply means under the nail.

The main subtypes of Melanoma are considered to be:

• Nodular melanoma
  
• Acral lentiginous melanoma
  
• Lentigo malignant
• Superficial

As well as some miscellaneous types

1. Desmoplastic
2. Mucosal lentiginous
3. Verrucous ⁽²⁾

Please note : Subungual melanoma is an uncommon form of Acral Melanoma that arises within the nail bed.

Subungual Melanoma

• According to Webster’s dictionary, the word subungual literally means situated or occurring under a toenail or fingernail. (10) This helps you to understand why this specific type of melanoma is named as it is.
• Is usually slow-growing and has many variations. This is part of the reason diagnosis is late.
• It is often misdiagnosed or overlooked and diagnosed late due to its multiple representations.
• Many times it is seen in men over the age of 50 and only in one finger.
• In general, it is a rare form of melanoma.
• Causes may include sun exposure, infections, human papillomavirus infections (HPV), epidermal dysplasia trauma, and human immunodeficiency virus (HIV). ⁽⁴⁾

Diagnosis of Subungual melanoma

• Biopsy of the lesion is the only definitive way to a diagnosis. ^(1–4)

Signs and Symptoms

Signs and symptoms are vague and because of this cause difficulty in diagnosis. All the symptoms can be attributed to many other diagnoses and many times are overlooked by the patient. ⁽⁶⁾

• Purulent drainage
• Pain
• Bleeding
• Dyschromia of the nail plate
• Deformity of the nail plate
• Ulceration
• Paronychia ⁽⁴⁾
• Non-healing wounds
• A mass which does not always have strange coloration.
• Discoloration of the nail bed
• A split in the nail bed

Subungual Melanoma Treatment

Treatment always depends on the stage and the progression of the lesion. If metastasis has occurred then the treatment of such will be more extensive.

• Targeting of specific DNA mutation and selection of potential drug which can target the growth. In this treatment, a biopsy is taken to help study the specific lesion and decide the best medication to eradicate it. ⁽²⁾
• Limited or wide surgical excision. The extent of the area removed will, of course, depend on the thickness of the melanoma.
• Amputation will only be done when necessary to prevent metastasis.
• Microscopic surgery helps to prevent removal of more tissue than necessary.  ⁽⁴⁾

Subungual Hematoma as compared to melanoma.

• Bleeding under the fingernail or toenail is considered a subungual hematoma.
• The cause of subungual hematoma is always trauma of some sort

1. Crushing injury
2. Blunt trauma
3. Sharp trauma

• The symptoms are severe pain, throbbing and collection of blood which appears under the nail. ⁽³⁾
• Symptoms are due to the pressure caused by the buildup of blood under the nail bed.
• At times treatment might be to drain the buildup of blood in order to decrease pressure and pain. ⁽¹⁾
• As long as there is no fracture in the bone this is acute.
• Removal of acrylic nails is indicated before any treatment can be prescribed.
• If a darkened area is noted under the nail and you do not remember a specific trauma the nail should be reviewed by a medical professional. ⁽³⁾

In this nail anatomy, you can see the distal portion of the germinal matrix which is where most subungual hematomas occur; this is also where subungual melanoma occurs. If the If the germinal matrix is injured due to the pressure buildup of a hematoma the nail may be lost. ⁽³⁾

Picture source 1 : medscapestatic.com

This image is showing the external view of the nail anatomy.

Picture source 2 : medscapestatic.com

Subungual Melanoma in Children

Although this type of melanoma is very rare among children the symptoms, diagnosis, and treatment all correlate with that of adults. Parents should always be aware of their children’s skin condition and assess any changes noted.

Subungual Melanoma Prognosis

• Early detection in subungual melanoma is the most important changes in its prognosis. ⁽⁵⁾
• Other items that will change the prognosis of subungual melanoma are:

1. Stage when diagnosed.
2. If there is ulceration noted
3. The S-phase fraction
4. If there is any bone invasion noted.
5. Diagnosis at late stages often occurs because it is rare and can often look like other disorders. This causes a worse prognosis.
6. Subungual melanoma has been noted to be more aggressive than other types of melanomas.
7. Reoccurrence infection in the lymph nodes depends on the initial diagnosis and treatment. ⁽⁵⁾

Subungual Melanoma Pictures

This photo shows a lesion which reoccurred after removal. After the reoccurrence ambulation was necessary. ⁽⁴⁾

This photo shows the finger after a debridement (cleaning of the area) and biopsy. The result was squamous cell carcinoma.

This Picture shows an MRI of a subungual lesion which did not spread any further into the finger.

Nail portion which was necessary to remove due to subungual melanoma diagnosis.

This picture demonstrates nail and tissue removal process.

This image shows a finger after the aforementioned nail/lesion removal and skin graft placement. ⁽⁵⁾

Images references : ncbi.nlm.nih.gov

source : onlinelibrary.wiley.com

This picture shows a 41yr old woman who went in for plastic surgery. When a biopsy was done she was diagnosed with subungual malignant melanoma. Surgery was done to remove the nail with a 0.5cm margin.  The area was covered with a skin graft and the patient received a low dose of chemotherapy. A full body scan showed that there was no metastasis. This malignancy is most commonly noted in the thumb ⁽⁴⁾

Subungual Acral Lentiginous Melanoma

• It is a malignant melanoma which shows up on the hands, feet, and subungual sites.
• Another more specific term used for subungual melanoma. The meaning is lesions noted in hairless areas.
• Its signs/symptoms, diagnosis, and treatment are the same as those mentioned in this article.

References:

1. http://emedicine.medscape.com/article/82926-overview
2. http://www.webmd.com/melanoma-skin-cancer/tc/melanoma-treatment-pdq-treatment—health-professional-information-nci-cellular-and-molecular-classification-of-melanoma.
3. http://www.webmd.com/skin-problems-and-treatments/bleeding-under-nail
4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4562831/
5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3418367/
6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4934499/
7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372915/
8. http://www.dermnetnz.org/hair-nails-sweat/melanoma-nailunit.html
9. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1243122/pdf/annsurg00060-0099.pdf
10. http://www.merriam-webster.com/medical/subungual