Identifying Skin Malignancies On The Distal Lower Extremity

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Continuing Education Course #112 — September 2003

I am very pleased to introduce the latest article, “Identifying Skin Malignancies On The Distal Lower Extremity,” in our new CE series. This series, brought to you by HMP Communications, consists of regular CE activities that qualify for one continuing education contact hour (.1 CEU). Readers will not be required to pay a processing fee for this course.

Benign and malignant lesions may appear similar on the surface. Indeed, understanding the clinical characteristics of various lesions, making the right call on key diagnostic measures and making an appropriate referral can go a long way toward early detection for your patients.

Utilizing a case study-driven approach, James Q. Del Rosso, DO, FAOCD, describes characteristics of various types of lesions and essential diagnostic pearls for separating benign lesions from malignant ones.

At the end of this article, you’ll find a 10-question exam. Please mark your responses on the postage-paid postcard and return it to HMP Communications. This course will be posted on Podiatry Today’s Web site ( roughly one month after the publication date. I hope this CE series contributes to your clinical skills.


Jeff A. Hall
Podiatry Today

INSTRUCTIONS: Physicians may receive one continuing education contact hour (.1 CEU) by reading the article on pg. 68 and successfully answering the questions on pg. 72. Use the postage-paid card provided to submit your answers or log on to and respond electronically.

ACCREDITATION: HMP Communications, LLC is approved by the Council on Podiatric Medical Education as a sponsor of continuing education in podiatric medicine.

DESIGNATION: This activity is approved for 1 continuing education contact hour or .1 CEU.

DISCLOSURE POLICY: All faculty participating in Continuing Education programs sponsored by HMP Communications, LLC are expected to disclose to the audience any real or apparent conflicts of interest related to the content of their presentation.

DISCLOSURE STATEMENTS: Dr. Del Rosso has disclosed that he is a member of the Speaker’s Bureau for 3M Pharmaceuticals, Dermik Laboratories, Bioglan Pharmaceuticals and Allergan.

GRADING: Answers to the CE exam will be graded by HMP Communications, LLC. Within 60 days, you will be advised that you have passed or failed the exam. A score of 70 percent or above will comprise a passing grade. A certificate will be awarded to participants who successfully complete the exam.


RELEASE DATE: September 2003.

EXPIRATION DATE:September 30, 2004.

LEARNING OBJECTIVES: At the conclusion of this activity, participants should be able to:
• discuss differential diagnoses for slow-growing, exophytic nodules;
• identify clinical characteristics of squamous cell carcinoma in situ;
• identify clinical characteristics of melanoma;
• discuss appropriate diagnostic measures for confirming clinical suspicions of melanoma; and
• detect eccrine poroma and discuss treatment options for the condition.

Sponsored by HMP Communications, LLC.

Be aware that superficial basal cell carcinoma may present with a very similar clinical appearance to squamous cell carcinoma in situ as seen above.
A 46-year-old Caucasian male patient presented with a six-month history of a slowly growing, firm and well-defined nodule measuring 1.2 cm in diameter. The exophytic and asymptomatic lesion was on the proximal plantar surface as seen above.
Pyogenic granuloma, also referred to as lobular capillary hemangioma, is a benign proliferative angiomatous neoplasm that tends to develop and grow rapidly over a period of a few weeks. The lesion may be pedunculated or associated with an epidermal collar
A 62-year-old female presented with two large, erythematous and scaly asymptomatic plaques on the medial surface of the leg (as shown above). The lesions were smaller initially and gradually expanded in diameter over the course of at least eight years.
The clinical appearance of this erythematous nodule is highly characteristic of a melanoma with a large central nodule, possibly arising within a congenital nevus.
Here is a melanoma on the lateral lower leg of a 38-year-old African-American female. Upon careful inspection, one can note the color variation as there is a lighter brown rim that comprises the periphery of the lesion.
By James Q. Del Rosso, DO, FAOCD

Cutaneous malignancies and benign neoplasms simulating malignancy commonly affect the distal lower extremity, including the foot. One may see a variety of malignancy categories such as epithelial tumors, adnexal neoplasms, melanoytic neoplasms, vascular neoplasms and soft tissue tumors. Histologic confirmation of diagnosis is essentially mandatory, warranting the need to send all tissue specimens, including biopsy, incisional and excisional specimens, for pathology examination.
In some cases, the pathologist may incorporate immunohistochemical stains to differentiate specific tumor types. Developing and maintaining a close working relationship with a pathologist who is board-certified or highly skilled in dermatopathology is very helpful in optimizing clinical and histologic correlation in order to maximize diagnostic accuracy.
With this in mind, let’s take a closer look at three cases in which skin malignancy or clinical simulants affect the distal lower extremity.

Case One Presentation: A Firm, Slow-Growing Exophytic Nodule
A 46-year-old Caucasian male presented with a six-month history of a slowly growing, firm, well-defined, exophytic and asymptomatic nodule measuring 1.2 cm in diameter (see below photo). The lesion was on the proximal plantar surface. Approximately three months prior to presentation, the patient self-treated the lesion (which he thought was a wart) for two weeks with a topical salicylic acid 17% liquid. There was no response.

The major neoplasms in this differential diagnosis include pyogenic granuloma, amelanotic melanoma, squamous cell carcinoma and eccrine poroma.
In this case, obtaining an excisional biopsy is preferable. Unless you have a clinical suspicion of melanoma, you may also obtain a deep saucerization biopsy, which encompasses the breadth of the neoplasm and is respresentative of its deeper aspect. The histologic evaluation confirmed eccrine poroma.
Eccrine poroma is a benign tumor which arises from eccrine glands, which are sweat glands naturally found in high concentration on the palms and soles.1,2 This type of tumor may simulate other malignant or benign tumors as mentioned above in the differential diagnosis. Eccrine poromas are typically solitary. They are usually slightly pedunculated or surrounded by a keratotic collarette. You will often see them on the plantar or lateral surface of the foot and they are usually less than 2 cm in diameter.1,2
The treatment of eccrine poroma is surgical excision with clear pathologic margins in order to reduce the risk of recurrence. The presence of multiple small eccrine poroma papules on the palms and soles (eccrine poromatosis) is an unusual and very rare presentation.3 Although relatively uncommon, malignant eccrine poroma (porocarcinoma), arising within a long-standing eccrine poroma, may remain localized or may metastasize, usually forming multiple cutaneous metastases with possible associated visceral metastases.4,5
Due to the absence of melanotic pigment, amelanotic melanoma may look similar to eccrine poroma, as may a nodular form of squamous cell carcinoma.

Pyogenic granuloma, also referred to as lobular capillary hemangioma, is a benign proliferative angiomatous neoplasm, which tends to develop and grow rapidly over a period of a few weeks (see photo at right).6 The lesion may be pedunculated or associated with an epidermal collarette. Occurring anywhere on the cutaneous surface, including the feet, pyogenic granuloma usually has a red, vascular appearance and may be friable with easy bleeding.

Case Two Presentation: Large Erythematous Plaques
A 62-year-old female presented with two large, erythematous scaly asymptomatic plaques on the medial surface of her leg (see below photo at left). The lesions started smaller and slowly expanded in radial diameter over the course of at least eight years.
Previous treatment with a topical antifungal (econazole) cream for approximately one month produced no change. Subsequent treatment with a high potency topical corticosteroid for three weeks also produced no response. The patient did not have any other similar lesions and there was no regional adenopathy upon palpation.

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