It is common for you to panic and scare when you notice any black spots on penis. But the good thing is that most of the lesions are harmless. Being said that, it is always good to get checked with the doctor and confirm its harmless nature, so that you won’t have to worry later. There are many conditions that can cause black spots on penis. Some of which are listed below:
Penile Melanosis, Penile melanotic macule or Genital Lentigines
Most common cause of dark spot on penis is penile melanosis. Penile melanosis is well-defined, oval, brown to black, flat patch that can be seen on glans penis (penis head) or shaft of penis. Sometimes they may have irregular border and change in color that can cause confusion with scary and malignant lesion like melanoma. In most cases your doctor may not need biopsy unless he sees something concerning. However, if you are older than 50, have family history of cancer, the number and size of the lesion are increasing, and lesions have atypical morphology, then it may warrant for biopsy. Luckily, most of the penile melanotic macules are harmless. Treatment is not necessary but for cosmetic purpose it can be removed with cryotherapy, and lasers or local excision.
Pigmented nevus (Moles) of the penis
Moles are quite common presentation on penis; they can be flat or slightly raised brown to dark color. They are usually harmless and do not requirement any treatment. But you should immediately visit doctor if you see any changes in size, color and texture of the lesion.
Post Inflammatory Hyperpigmentation (PIH)
Another cause of black spots on penis is post inflammatory hyperpigmentation which is quite common. Minor infections like folliculitis, minor injuries or even irritation can leave black pigmentation after healing which will fade with time. These minor injuries or irritation can be so mild that you may not have noticed, all you notice is post inflammatory hyperpigmentation.
Sometimes genital warts (Bowenoid papulosis) can also appear pigmented that can create confusion with other disease. They care caused by human papilloma virus and are sexually transmitted. They are usually single or multiple red, brown to flesh color bumps with flat surface and commonly seen on shaft of penis. Bowenoid papulosis is considered to be transitional state between genital warts and Bowen disease and has potential to be malignant.
Angiokeratomas of the Penis
Although most commonly seen on the scrotum, angiokeratomas can also arise in shaft and glans of the penis. They look like tiny black, blue or red domed-shaped bumps. Most of the cases are asymptomatic, but some may complain of pain and mild itching. Although harmless, it can cause considerable worry and can be bothersome.
Primary Penile Melanoma
Penile melanoma is rare malignant skin cancer of the elderly. The lesion frequently affects the glans, followed by foreskin, the shaft and the tip of urethra. Early stage of the disease, primary penile melanoma can mimic several other harmless lesions, so early correct diagnosis is very important that can affect the outcome of the disease. Biopsy can aid in correct diagnosis.
Primary Kaposi Sarcoma of the Penis
Primary penile kaposi sarcoma sometimes can also present as pigmented patch on penis. Kaposi sarcoma localized to the penis is very rare and affects more in HIV positive individual. Glans penis is more common, followed by foreskin, coronal sulcus, penile body, frenulum and urethral meatus. Kaposi sarcoma can be treated with local surgical excision, electrosurgery, cryotherapy, chemotherapy, laser therapy and radiation therapy.
There are several other conditions that are either limited to genital area or associated with other cutaneous presentation on any parts of the body. Some of these conditions are:
Eruptive syringoma of the penis
Fixed drug eruption
Genital Lichen Planus
There may still be many cases that can present as black spot on penis that might not have been included here. Please consult dermatologist if you notice any unusual dark spot on your penis. Almost anything can be cured if diagnosed early.