1. What essential questions does one still need to ask to help make the diagnosis?
2. What is the tentative diagnosis?
3. Can you list at least three differential diagnoses?
4. What features of this condition differentiate it from other conditions in your differential?
5. What is the suitable treatment of this condition?
When A Patient Has An Unusual Growth On A Toe
A 43-year-old African-American male presents to the office with an irritated fourth toe with no known trauma to the toe. There is a horny projection of skin coming from the posterior nail fold with a nail-like structure at the tip. It has been present for the past two years and had recently become larger.
The lesion is asymptomatic except for physical inconveniences.
The patient reports that the toe is painful only in shoes. The patient works as a custodian and spends a lot of time on his feet. He has recent onset diabetes of three years but has not been to a podiatrist in the last two years. The patient has no other medical history concerns other than the NIDDM. He denies seizures and other past medical history. There was no family history of any systemic issues, mental retardation or polydactly.
The examination revealed a 1.8 cm long, non-tender, firm, skin-colored growth with a rough surface at the tip projected distally from the proximal nail fold of the toe at the level of the middle phalanx. The growth was in contact with the nail and had caused a longitudinal groove or deformity of the nail plate. The patient was just aware that a piece of skin was causing irritation to the toe. There was no bleeding or ulceration of the growth.
A careful examination revealed no other growths on the other toes or foot. Evaluation of the entire body revealed no other dermatological findings.
Pertinent Diagnostic Considerations
When a patient comes to the office with a growth on the skin, one has to try to classify the lesion in order to aid in the diagnosis. All lesions/ skin tumors can be grouped according to different classification systems. One of the systems looks at histological origin, the age of the patient, location of the lesion and clinical appearance/ topography.1
In terms of histological origin —which is divided into epidermal, mesodermal and nevus cell tumors as well as lymphomas and myeloses — this patient’s lesion fits into the epidermal cell tumor classification.
Some of the more common tumors in adults include: warts, nevi, cysts, skin tags, keloids, lipomas and pyogenic granulomas. In terms of location, the more common skin lesions found on the hands and feet are: warts, nevi, seborrheic keratosis, lentigo, myxoid cyst (proximal nail fold), squamous cell carcinoma, glomus tumor (nail bed), ganglion, acral lentiginous melanoma, pyogenic granuloma, acquired digital fibrokeratoma and traumatic fibroma.1,2
The most important diagnostic factor is clinical appearance or topography since many skin lesions have clinical characteristics common to several lesions. Since the growth in question is basically a raised, skin-colored tumor, the list of the more common lesions encountered includes: warts, skin tags, nevi, cysts, lipomas, keloids and basal cell carcinoma.
The less common ones include: infantile digital fibroma, cutaneous horn, acrochordons, osteochondroma, subungual exostosis, squamous cell carcinoma and superficial acral fibromyxoma. If there is any question as to what the growth really is, one should take a biopsy.