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What Is This Progressively Growing Lesion on a Man’s Lower Extremity?

Gregory A. Lawson, MD, MPH

1Sparrow Health System, Lansing Michigan
2Michigan State University, College of Human Medicine, Department of Family Medicine, East Lansing, Michigan

Lawson G. What is this progressively growing lesion on a man’s lower extremity? Consultant. Published online April 22, 2021. doi:10.25270/con.2021.04.00013

Received December 28, 2020. Accepted January 12, 2021.

The author reports no relevant financial relationships.

Gregory A. Lawson, MD, MPH, Sparrow Medical Group Ionia, 500 South Washington Street, Ionia, MI 48846 (


A 62-year-old man presented to the clinic with an enlarging lesion on his left shin. The lesion had progressively grown in size and, in the last few weeks, has been associated with a yellowish discharge, which prompted the patient to seek care.

Six months prior to presentation, the patient had had a biopsy for a nonhealing ulcer, which he had developed after experiencing trauma to the shin, at the location of the current lesion. According to him, the initial lesion was about 1 cm in diameter. However, since the biopsy, the lesion has changed in size and characteristic.

The patient had a 25 pack-year smoking history and diagnoses of hypertension, hyperlipidemia, osteoarthritis, and chronic obstructive pulmonary disease. He denied pain, fever, and chills. His current medications included lisinopril, atorvastatin, and diclofenac sodium/misoprostol.

A physical examination was conducted, findings of which were significant for an approximately 3-cm violaceous, brownish plaque on an atrophic, telangiectatic base on the left shin (Figure). The lesion had a moderate amount of yellow crusting and perilesional erythema. No tenderness was appreciated on the lesion. Diminished pedal pulses bilaterally were also noted.

Figure. growing lesion on the lower leg



Answer and discussion on next page.

Answer: B. Necrobiosis lipoidica

Given the patient’s history and physical examination findings, coupled with the progressive development of the lesion after initial trauma and then after the biopsy, it is characteristic of necrobiosis lipoidica.

Biopsy results confirmed the diagnosis, with the dermis showing perivascular mixed inflammatory cell infiltrate of lymphocytes, histiocytes, and neutrophils and patchy areas of degenerated collagen bundles. The inflammatory infiltrate and degenerated collagen were arranged in a laminated array that involved the full thickness of the dermis and extended to the subcutis. Focal numerous plasma cells were present around the deep dermis.

Discussion. Necrobiosis lipoidica is an uncommon, chronic granulomatous disease of the skin that mostly affects young and middle-aged adults.1,2 Skin involvement usually begins as reddish-brown or violaceous papules or nodules and progresses to yellowish-brown, atrophic, telangiectatic plaques. The lower extremities are the most common sites of involvement, and ulceration is a common complication.1

Necrobiosis lipoidica can present with the Koebner phenomenon, which is the development of new skin diseases at sites of previous skin trauma, as was the case in my patient.3 Because necrobiosis lipoidica is commonly associated with diabetes, evaluation of patients with necrobiosis lipoidica should include screening for diabetes or assessing glycemic control.3

The treatment for necrobiosis lipoidica focuses on management of symptoms of the disease by inhibiting the inflammatory process and healing the ulcerations. As such, the treatment can be challenging. Corticosteroids, either topical or intralesional, are frequently used as initial therapy.2,3 Other therapies used include topical tacrolimus and topical psoralen plus ultraviolet A.2,3 As ulceration is a common complication of this condition, the avoidance of trauma is essential.

Differential diagnosis. Cutaneous manifestation of sarcoidosis infrequently may present with necrobiosis lipoidica-like skin lesions. In such cases, the histologic findings are useful for distinguishing between these diseases. Large, well-formed, naked, epithelioid granulomas and absent necrobiosis support a diagnosis of sarcoidosis. Multisystem involvement (ie, lung, eye, lymph nodes) also favors a diagnosis of sarcoidosis.4

Localized granuloma annulare is characterized by skin-colored to violaceous lesions. Usually, the epidermis has attenuated surface markings. Annular rings with solitary firm papules or nodules may be present. Localized granuloma annulare has a predilection for the feet, ankles, lower extremities, and wrists.5 Unlike necrobiosis lipoidica, yellow discoloration and telangiectasias typically are absent. There are rare reports of patients who have presented with both disorders.6

Stasis dermatitis is an inflammatory skin condition that most commonly occurs on the lower extremities in the setting of chronic venous insufficiency. It may present with reddish, scaly, and discolored patches and plaques, as well as pitting edema.7

Keratoacanthoma is a common low-grade, fast-growing skin tumor with a centralized keratinous plug.8 It rapidly grows over some weeks to months, followed by spontaneous resolution in 4 to 6 months in the majority of cases.7

Patient outcome. Initial therapy with clobetasol ointment was not effective. The patient was lost to follow-up for 9 months. When he presented again at my clinic, more significant ulceration was noted, and he was referred to the wound clinic. There, the lesion was treated with crust removal, antimicrobial dressing, and superabsorbent wrap. The patient was then transitioned to management by a dermatologist. Padded protective shin wear and skin care for atrophic areas to reduce the risk of skin break down were recommended.


1. Kota SK, Jammula S, Kota SK, Meher LK, Modi KD. Necrobiosis lipoidica diabeticorum: a case-based review of literature. Indian J Endocrinol Metab. 2012;16(4):614-620.

2. Pourang A, Sivamani RK. Treatment-resistant ulcerative necrobiosis lipoidica in a diabetic patient responsive to ustekinumab. Dermatol Online J. 2019;25(8):13030/qt2q05z4rw.

3. Lepe K, Riley CA, Salazar FJ. Necrobiosis lipoidica. In: StatPearls [Internet]. StatPearls Publishing; 2021.

4. Chiba T, Takahara M, Nakahara T, et al. Cutaneous sarcoidosis clinically mimicking necrobiosis lipoidica in a patient with systemic sarcoidosis. Ann Dermatol. 2012;24(1):74-76.

5. Ghadially R, Szabo AZ. What are the types of granuloma annulare? Medscape. Updated October 15, 2020. Accessed April 2020.

6. Souza FH, Ribeiro CF, Pereira MA, Mesquita L, Fabrício L. Simultaneous occurrence of ulcerated necrobiosis lipoidica and granuloma annulare in a patient: case report. An Bras Dermatol. 2011;86(5):1007-1010.

7. Zito PM, Scharf R. Keratoacanthoma. In: StatPearls [Internet]. StatPearls Publishing; 2020.

8. Chuang TY. Keratoacanthoma. Medscape. Updated February 24, 2020. Accessed December 2020.