Observation | Dermatol Pract Concept 2011;1(1):10 49 Background: Basal cell carcinoma usually occurs in sun exposed areas of older male individuals. objectives: To emphasize the importance of histological step sections in the pursuit of the correct diagnosis when microscopic findings do not correspond to clinical hypothesis. Patient: 21-year-old female with a superficial basal cell carcinoma in pubic region diagnosed after histological step sections and treated with topical imiquimod. Conclusions: Although very rare, basal cell carcinomas do occur in young patients and, at times, on areas of the body where they are not conventionally seen. Step sections are an important tool that dermatopathologists should use on a regular basis to enhance diagnostic accuracy. aBstraCt Saved by step sections: an unusual presentation of basal cell carcinoma Betina Werner, M.D.1, Fabiane Mulinari-Brenner, M.D.2 1Dermatopathologist, Curitiba, Parana, Brazil 2Dermatologist, Curitiba, Parana, Brazil Key words: basal cell carcinoma, step sections, pubic region, differential diagnosis, biopsy Citation: Werner B, Mulinari-Brenner F. Saved by step sections: an unusual presentation of basal cell carcinoma. Dermatol Pract Concept 2011;1(1):10. http://dx.doi.org/10.5826/dpc.0101a10. editor: Harald Kittler, M.D. received: october 1, 2010; accepted: December 17, 2011; Published: october 31, 2011 Copyright: ©2011 Werner et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Betina Werner, M.D., rua Dr. Nelson de Souza Pinto, 759, 82200-060 Curitiba, Parana, Brazil. Tel. 55 41 9116 0525. Email: betina.werner@gmail.com. Introduction Basal cell carcinomas are usually found in sun exposed areas of older individuals, especially the head and neck [1, 2, 3]. The incidence of basal cell carcinoma in patients younger than 50 years old, was 5% in one Brazilian study [4], and these were mainly in regions exposed to sunlight. Although several cases of basal cell carcinoma in the vulva can be found in the literature [5–8], only one case reported it to occur in the pubic region [9]. We describe a young female patient with an enlarging erythematous macule on the pubic region that was diagnosed as superficial basal cell carcinoma. There was no clinical sus- picion of malignant neoplasia, however, that diagnosis was possible by performing histological step sections. Case report A 21-year-old female presented a 2 cm erythematous macule on the pubis that had been slowly enlarging over a period of 18 months (Figure 1). Her main complain, actually, was dif- fuse hair thinning and scalp scaling, which was interpreted as androgenetic alopecia associated with seborrheic derma- Dermatology PrACTICAL & CoNCEPTUAL www.derm101.com 50 Observation | Dermatol Pract Concept 2011;1(1):10 titis. She was otherwise healthy with no other significant skin abnormalities. Mycologic tests (direct examination with potassium hydroxide and culture) done on the pubic lesion were negative. No improvement was seen after topical cor- ticosteroid for 10 days. A skin biopsy (3 mm punch) was performed with the following clinical hypothesis: seborrheic dermatitis, eczema, psoriasis, tinea incognita. Histological sections (Figures 2A, 2B, 2C) showed a well-demarcated area of ulceration with crust. Adjacent epidermis depicted irregu- lar acanthosis and prominent spongiosis with inflammatory cells in exocytosis; superficial and mid-dermis presented a dense inflammatory infiltrate composed mainly of lympho- cytes. Step sections were ordered because skin ulceration is unusual in those clinical differential diagnoses listed. New sections (Figures 3A, 3B and 3C) surprisingly showed neo- plastic blocks attached to the epidermis demonstrating slit- like retraction of the palisaded basaloid cells from the adja- cent stroma. The diagnosis of superficial basal cell carcinoma was yielded. The patient started topical imiquimod cream (Figure 4A), five days a week for six weeks. Severe inflam- mation was noticed in week three (Figure 4B), followed by crusting in week six (Figure 4C), and complete healing. No signs of recurrence was seen at a six-month follow-up (Fig- ure 4D). Discussion To the best of our knowledge, this is the first case report of superficial basal cell carcinoma in the pubic region of a young adult female. The only case we found in the literature occurring in the pubic region was a polypoid basal cell carci- noma (fibroepithelioma of Pinkus) measuring 7.1 × 5.0 × 2.2 cm in a 61-year-old woman – a totally different clinical and histological setting from the case reported herein. Figure 1. Clinical appearance: 2 cm erythematous patch with focal crusting and scaling. Figure 2. a: Panoramic view of first section showing well demar- cated area of ulceration of the epidermis with crust. original magni- fication (objective) x20; B: Epidermis with ulceration and irregular acanthosis; dense inflammatory infiltrate composed mainly of lym- phocytes in superficial and mid-dermis. original magnification (ob- jective) x100; C: Detail of epidermis with scale crust and prominent spongiosis with inflammatory cells in exocytosis. original magnifi- cation (objective) x200. A B C Observation | Dermatol Pract Concept 2011;1(1):10 51 Another feature that contributes to the peculiarity of this case is that the diagnosis of basal cell carcinoma was possible because step sections were ordered. The order was based on the odd aspect of the first hematoxylin and eosin slide where an area of ulceration could be seen. A PAS stain with diastase was already performed and had not given any enlightenment on the matter. The intention of ordering deeper sections was to find the explanation for that ulceration and to rule out the remote possibility of a bullous disease or of herpes simplex virus infection. Actually, in the author’s (BW) own experience, herpes simplex virus infection is the “champion” among the diagnoses made by deeper/step sections, especially when fol- licular herpes infection is present. resnik and DiLeonardo [10] reported three such cases, a setting they called “herpes incognito.” Some studies have approached the matter of step sec- tioning in dermatopathology [11–14] and its usefulness in enhancing diagnostic accuracy and cost-benefit issues are the major concerns. These authors were all convinced that 30–37% of their cases benefitted from that practice [11–14]. The higher rate of ordering step sections was obtained in a retrospective study by Maingi and Helm [11], where the dermatopathologist felt compelled to order deeper sections based on histological aspects. This study best reflects what in reality occurs in a dermatopathology service – 63% of the step sectioned cases could be signed out without ordering them, with no change in diagnosis. on the other hand, if no step sectioning were performed, 37% of the patients would not benefit maximally from the diagnostic power of skin biopsy. Step sectioning can be cru- cial to diagnosis, like what happened in the case reported by us. Figure 3. a: Panoramic view after step sectioning. Ulcerated area was associated to a superficial neoplasia demonstrating slit-like retraction from the subjacent dermis. original magnification (objective) x20; B: Closer view of superficial basal cell carcinoma. original magnifi- cation (objective) x100; C: Detail of neoplastic blocks with palisaded basaloid cells and characteristic separation from papillary dermis. original magnification (objective) x200. Figure 4. A: Clinical aspect before treatment; B: Three weeks after imiquimod cream with severe inflammation; C: Six weeks after Im- iquimod cream with partial healing and focal crusting; D: Six months after treatment. Complete healing and no signs of recurrence. A B C 52 Observation | Dermatol Pract Concept 2011;1(1):10 references 1. roewert-Huber J, Lange-Asschenfeldt B, Stockfleth E, Kerl H. Ep- idemiology and aetiology of basal cell carcinoma. Br J Dermatol 2007;157(suppl 2):47–51. 2. Lear W, Dahlke E, Murray CA. Basal cell carcinoma: review of epidemiology, pathogenesis, and associated risk factors. J Cut Med Surg 2007;11(1):19–30. 3. Carucci JA, Leffell DJ. Basal cell carcinoma. In: Wolff K, Gold- smith LA, Katz SI, Gilchrest BA, Paller AS, Leffell DJ (eds.). Fitz- patrick’s Dermatology in General Medicine. 7th ed. New York: The McGraw-Hill Companies, Inc., 2008:1036-42. 4. Almeida AC, Yamashita T, Conte B, Mattos AC, Veríssimo rP, Ferreira MC. [Frequency of basal cell carcinoma in a population younger than 50 years of age: clinical study and literature review]. An Bras Dermatol 2009;84(6):692-4. 5. Thomas rH, McGibbon DH, Munro DD. Basal cell carcinoma of the vulva in association with vulval lichen sclerosus et atrophicus. J royal Soc Med 1985;78(Suppl 11):16-18. 6. Mateus C, Fortier-Beaulieu M, Lhomme C, et al. Basal cell carcinoma of the vulva: 21 cases. Ann Dermatol Venereol 2001;128(1):11-5. 7. Pisani C, Poggiali S, La De Padova L, Andreassi A, Bilenchi r. Basal cell carcinoma of the vulva. J Eur Acad Dermatol Venereol 2006;20(4):446–8. 8. Suda T, Kakinuma H. Erosive velvety lesion on the vulva – vulvar basal cell carcinoma. Arch Dermatol 2006;142(3):385-90. 9. Misago N, Suzuki Y, Miura Y, Narisawa Y. Giant polypoid basal cell carcinoma with features of fibroepithelioma of Pinkus and extensive cornification. Eur J Dermatol 2004;14(4):272-5. 10. resnik KS, DiLeonardo M. Herpes incognito. Am J Dermatopa- thol.2000; 22(2):144-50. 11. Maingi CP, Helm KF. Utility of deeper sections and special stains for dermatopathology specimens. J Cutan Pathol 1998;25(3):171- 5. 12. Carag Hr, Prieto VG, Yballe LS, Shea rS. Utility of step sections: demonstration of additional pathological findings in biopsy samples initially diagnosed as actinic keratosis. Arch Dermatol 2000;136(4):471-5. 13. Guille Dr. Accurate diagnosis of cutaneous keratinocytic neo- plasms: the importance of histological step sections (and other factors). Arch Dermatol 2000;136(4):535-7. 14. Bruecks AK, Shupe LM, Trotter MJ. Prospective step sections for small skin biopsies. Arch Pathol Lab Med 2007;131(1):107–11.