What Is This Exophytic Lesion on the Left Upper Helical Rim?

A healthy 42-year-old woman with fair skin (Fitzpatrick type 2) and no significant past medical history presented to the clinic with concerns about a dry, rough lesion on her left ear. The lesion had been present for approximately 3 months and was located at the site of a previous piercing. She recalled several sunburns as a teenager, did not endorse the use of tanning beds, and had no family history of nonmelanoma skin cancer. The patient denied pruritus, pain, or bleeding at the site, and a review of systems was unremarkable. On physical examination, a circumscribed, hard lesion measuring approximately 0.8 cm x 0.8 cm was appreciated on the helical rim of her left ear (Figure). A shave biopsy was obtained for further investigation. 

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Squamous Cell Carcinoma 

In histology, an exoendophytic verrucous squamous proliferation with marked hyperkeratosis was found. The patient was subsequently referred for Mohs micrographic surgery and during debulking, a diagnosis of well-differentiated squamous cell carcinoma (SCC) was confirmed. 

Cutaneous SCC is one of the most common skin cancers in the United States, second to basal cell carcinoma (BCC).¹ SCC results from uncontrolled production of stratified squamous epithelium and nonsquamous epithelia.² Squamous epithelial tissue is located in the skin, esophagus, oral cavity, urinary tract, and airway; therefore, SCC can appear on multiple anatomic locations. Common subtypes include verrucous SCC, papillary SCC, and keratoacanthoma. 

The incidence of nonmelanocytic SCC was 6.2% globally in 2020, with less than 10% of lesions reaching regional metastasis.^3,4 In the United States alone, more than 1 million people are diagnosed with SCC annually, with an increased incidence in both men and women.⁵ Ultraviolet (UV) radiation is the most significant risk factor for developing SCC. Additional causes include burn scars, ulcers, and inflammation.¹ It disproportionally affects Caucasian men older than age 50 who have a substantial history of UV radiation exposure. People should also be made aware that SCC disproportionately affects African American patients and is the second most common skin cancer in Hispanic and Asian individuals.⁶ In comparison to Caucasian patients, people of color are more frequently diagnosed with a worse prognosis because they have the tendency to present with a more advanced disease stage. Individuals who are immunosuppressed are also at an increased risk for SCC. Rare cases of well-differentiated SCC have occurred in patients with extended earlobe piercing sites, as seen in our patient.⁷ Similarly, SCC can arise as Margolin ulcers in areas of pre-existing scar tissue consistent with repeated trauma, such as old burn scars or pressure ulcers.⁸ 

SCC arises from a precursor lesion called actinic keratosis (AK), which is the result of skin damage from UV radiation (UVA/UVB). Although the genetic component is still being explored, data have shown that the p53 gene pathway plays a role in the development of SCC. The p53 pathway normally inhibits damaged DNA from replication; however, if mutated, it can cause uncontrolled replication of cells with impaired DNA, leading to malignancy. Histologically, SCC is classified as well-differentiated, moderately differentiated, and poorly differentiated.³ A frequently encountered low-grade form of SCC is Bowen disease, which appears as hyperkeratosis and parakeratosis on histology.⁹ It regularly appears on mucosal surfaces and nail beds as erythematous scaly patches or plaques. Appearing similarly, Bowenoid papulosis is another variation of SCC associated with parakeratosis, disordered dyskeratosis, and metaphase mitosis.¹⁰ 

The vast majority of invasive SCC will arise from the tumorous progression of AK and show infiltrative cells invading the basement membrane and extending into the dermis layer. Similarly, tumor cells will show keratinizing pearls and inflammatory infiltrates under the microscope.¹¹ On histopathology, they present as irregular neoplastic keratinocytes with dermal invasion. Other histologic variants of SCC include keratoacanthomas, which develop as dome-shaped nodules with significant central hyperkeratosis.¹² Verrucous carcinoma, another subtype of SCC, appears on histology as a well-differentiated epithelial lesion with “pushing borders.”¹³ These subcategories are far less commonly encountered in patients with SCC; however, physicians should still be aware of their existence and basic characteristics. 

The appearance of SCC varies depending on the anatomic location and patient history. Classically, it presents on the face, neck, scalp, dorsal hands, and shins because those areas are vulnerable to increased sun exposure and UV radiation.¹ It also frequently appears as an erythematous scaly patch or elevated plaque, which will often go unrecognized by patients. The presentation of invasive SCC is more severe and has the power to ulcerate and become patchy, papulonodular, or exophytic.¹⁴ Additional features include telangiectasias, keratin scale, and the manifestation of cutaneous horns. 

The gold standard for SCC diagnosis is skin biopsy in all patients with clinical suspicion for SCC. Other diagnostic tools readily used by dermatologists include dermoscopy and videodermoscopy, which are noninvasive techniques that analyze the color and architecture of the epidermis, dermal-epidermal junction, and papillary dermis using 10-fold magnification.¹⁵ Reflectance confocal microscopy is an additional noninvasive tool that uses the structural patterns of the spinous-granular layer and dermal papillae.¹⁶ High-frequency ultrasonography and optical coherence tomography may also be used. 

SCC prognosis is good, with a 99% survival rate if detected early. Otherwise, the 5-year survival for advanced SCC is lower than 40%. Risk factors that contribute to worse prognosis include having a darker skin tone, immunosuppression, and extensive radiation therapy exposure.¹⁷ Complications include metastasis, aesthetic dissatisfaction, and pain. Global organizations such as the National Comprehensive Cancer Network (NCCN) have published guidelines discussing the differences between high-risk and low-risk tumors and related prognostic factors. Tumor size, TNM (tumor, node, metastasis) staging, growth rate, and histologic differentiation are all important prognostic indicators of patient outcomes.¹⁸ According to NCCN, lesions that are greater than 4 cm, found within the nerve sheath, poorly differentiated, and have accelerated growth are considered very high risk.¹⁹ 

Differential diagnosis for SCC includes AK, BCC, lichen simplex chronicus, verruca vulgaris, and scar tissue (eTable).^1,20-25 

Factors such as cost, age, and tumor characteristics are all important to consider when deciding if a patient is an ideal candidate for surgery, which is the mainstay of treatment for SCC. Excisional surgery is performed by a surgeon removing the entire tumor along with margins of normal skin tissue until the surrounding skin is considered cancer free.²⁶ Dermatologists use the appropriate criteria score from the American Academy of Dermatology to determine the indication for Mohs micrographic surgery, a highly precise and effective surgical technique that involves removing the tumor in stages to spare the greatest amount of healthy skin.²⁷ The tissue is normally evaluated under a microscope to ensure that no cancer cells persist. NCCN recommends surgical excision with 4-mm to 6-mm margins for low-risk SCC and greater than 6 mm for high-risk tumors. The European Dermatology Forum recommends the use of Mohs surgery for tumors between 6 mm and 10 mm.²⁸ Global guidelines vary depending on the organization; therefore, it is important to consider multiple factors when determining the best treatment for patients. 

Electrosurgery, laser surgery, and radiotherapy are reserved when other methods are unsuccessful or if the cancer is superficial and has not yet invaded deeper cutaneous layers. During treatment, it is imperative for providers to educate patients on the importance of sun safety and protection from UV radiation. They should be advised to use a broad-spectrum sunscreen, wear protective clothing, avoid indoor tanning beds, have routine skin exams, and limit the amount of time spent in the sun. 

In our case, the patient was diagnosed with SCC in an unusual location, the helical rim. The flesh-colored exophytic lesion appeared similar to verruca vulgaris, so it required a skin biopsy to confirm the presence of SCC. The patient was treated the same day as initial presentation with Mohs surgery. Her lesion required a singular excision stage and was repaired using a linear layered approach for optimal wound healing. She was instructed to follow up twice a year and was educated on preventive measures, such as wearing sunscreen, reducing UV exposure, and monthly skin checks. 

SCC is the second most common skin cancer in the United States. It has a relatively good prognosis with high survival rates if detected early. Although it is considered rare for SCC to appear on the ears, it can technically emerge anywhere on the body. Skin biopsy is required to make a definitive diagnosis and standard treatment requires surgery. 

1. Howell JY, Ramsey ML. Squamous cell skin cancer. In: StatPearls [Internet]. StatPearls Publishing; 2023. 

2. Sánchez-Danés A, Blanpain C. Deciphering the cells of origin of squamous cell carcinomas. Nat Rev Cancer. 2018;18(9):549-561. doi:10.1038/s41568-018-0024-5 

3. Cocuz IG, Popelea MC, Manea A, Niculescu R, Sabau AH, Cotoi OS. Epidemiological and histological characteristics of the cutaneous squamous cell carcinoma—a single centre-study. Acta Marisiensis. Seria Medica. 2023;69(4). doi:10.2478/amma-2023-0043 

4. Szewczyk M, Pazdrowski J, Golusiński P, et al. Outdoor work as a risk factor for high-grade cutaneous squamous cell carcinoma of the head and neck. Postepy Dermatol Alergol. 2018;35(4):408-412. doi:10.5114/ada.2018.75841 

5. Planelles-Ramos MV, Araujo Pérez R, Delcampo-Novales M, Flores-Saldaña M. Skin lesions. Rev Esp Sanid Penit. 24(2):75-76. doi:10.18176/resp.00053 

6. Bradford PT. Skin cancer in skin of color. Dermatol Nurs. 2009;21(4):170-178. 

7. Hagiwara K, Shinzato R, Higa T, Toyama K, Miyazato H, Nonaka S. A case of double cancer: a squamous cell carcinoma arising from a long pierced site on the left earlobe and a solid tubular carcinoma of the left breast. J Dermatol. 1994;21(9):664-669. doi:10.1111/j.1346-8138.1994.tb01813.x 

8. Pekarek B, Buck S, Osher L. A comprehensive review on Marjolin’s ulcers: diagnosis and treatment. J Am Col Certif Wound Spec. 2012;3(3):60-64. doi:10.1016/j. jcws.2012.04.001 

9. Yanofsky VR, Mercer SE, Phelps RG. Histopathological variants of cutaneous squamous cell carcinoma: a review. J Skin Cancer. 2011;2011:210813. doi:10.1155/2011/210813 

10. Chamli A, Zaouak A. Bowenoid papulosis. In: StatPearls [Internet]. StatPearls Publishing; 2024. 

11. Caruntu A, Moraru L, Lupu M, et al. Assessment of histological features in squamous cell carcinoma involving head and neck skin and mucosa. J Clin Med. 2021;10(11):2343. doi:10.3390/jcm10112343 

12. Tisack A, Fotouhi A, Fidai C, Friedman BJ, Ozog D, Veenstra J. A clinical and biological review of keratoacanthoma. Br J Dermatol. 2021;185(3):487-498. doi:10.1111/bjd.20389 

13. Koch BB, Trask DK, Hoffman HT, et al. National survey of head and neck verrucous carcinoma: patterns of presentation, care, and outcome. Cancer. 2001;92(1):110-120. doi: 10.1002/1097-0142(20010701)92:1<110::aid-cncr1298>3.0.co;2-k 

14. Combalia A, Carrera C. Squamous cell carcinoma: an update on diagnosis and treatment. Dermatol Pract Concept. 2020;10(3):e2020066. doi:10.5826/ dpc.1003a66 

15. Warszawik-Hendzel O, Olszewska M, Maj M, Rakowska A, Czuwara J, Rudnicka L. Non-invasive diagnostic techniques in the diagnosis of squamous cell carcinoma. J Dermatol Case Rep. 2015;9(4):89-97. doi:10.3315/jdcr.2015.1221 

16. Fania L, Didona D, Di Pietro FR, et al. Cutaneous squamous cell carcinoma: from pathophysiology to novel therapeutic approaches. Biomedicines. 2021;9(2):171. doi:10.3390/biomedicines9020171 

17. Cheng J, Yan S. Prognostic variables in high-risk cutaneous squamous cell carcinoma: a review. J Cutan Pathol. 2016;43(11):994-1004. doi:10.1111/cup.12766 

18. Endo Y, Tanioka M, Miyachi Y. Prognostic factors in cutaneous squamous cell carcinoma: is patient delay in hospital visit a predictor of survival? ISRN Dermatol. 2011;2011:285289. doi:10.5402/2011/285289 

19. Brancaccio G, Briatico G, Pellegrini C, Rocco T, Moscarella E, Fargnoli MC. Risk factors and diagnosis of advanced cutaneous squamous cell carcinoma. Dermatol Pract Concept. 2021;11(Suppl 2):e2021166S. doi:10.5826/dpc.11S2a166S 

20. Noroozi N, Zakerolhosseini A. Differential diagnosis of squamous cell carcinoma in situ using skin histopathological images. Comput Biol Med. 2016;70:23-39. doi:10.1016/j.compbiomed.2015.12.024 

21. Marques E, Chen TM. Actinic keratosis. In: StatPearls [Internet]. StatPearls Publishing; 2023. 

22. McDaniel B, Badri T, Steele RB. Basal cell carcinoma. In: StatPearls [Internet]. StatPearls Publishing; 2023. 

23. Prajapati V, Barankin B. Dermacase. Lichen simplex chronicus. Can Fam Physician. 2008;54(10):1391-1393. 

24. Ural A, Arslan S, Ersöz Ş, Değer B. Verruca vulgaris of the tongue: a case report with literature review. Bosn J Basic Med Sci. 2014;14(3):136-138. doi:10.17305/ bjbms.2014.3.29 

25. Marshall CD, Hu MS, Leavitt T, Barnes LA, Lorenz HP, Longaker MT. Cutaneous scarring: basic science, current treatments, and future directions. Adv Wound Care (New Rochelle). 2018;7(2):29-45. doi:10.1089/wound.2016.0696 

26. Shuber E, Abdulhussein D, Sinclair P, Kadhum M. Who should carry out skin cancer excisions? A systematic review. J Cutan Aesthet Surg. 2019;12(3):153-157. doi:10.4103/JCAS.JCAS_174_18 

27. Prickett KA, Ramsey ML. Mohs micrographic surgery. In: StatPearls [Internet]. StatPearls Publishing; 2023. 

28. Nahhas AF, Scarbrough CA, Trotter S. A review of the global guidelines on surgical margins for nonmelanoma skin cancers. J Clin Aesthet Dermatol. 2017;10(4):37-46. 

Madeline Brown is a medical student at the University of Maryland School of Medicine in Baltimore, MD. Dr Khachemoune is the Derm DX section editor and a dermatologist affiliated with SUNY Downstate and VA New York Harbor Care-Brooklyn in Brooklyn, NY. 

Disclosure: The authors report no relevant financial relationships.