Dermatology: Practical and Conceptual DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Quiz | Dermatol Pract Concept 2014;4(2):14 67 Below find the answer and discussion to the quiz by Savoia et al. presented in the previous issue of Dermatology Practi- cal & Conceptual (http://dx.doi.org/10.5826/dpc.0401a12). Diagnosis Pigmented cutaneous squamous cell carcinoma (PCSCC). Clinical course The patient had no evidence of local recurrence or metastasis during 12 months of follow-up. Answer and explanation PCSCC is a variant of invasive squamous cell carcinoma, with less than 20 cases reported, to our knowledge, in the English literature [1,2]. PCSCC had been more often reported to occur in the oral mucosa and conjunctiva [3]. Pigmentation is probably due to cytokines secreted by tumoral cells that stimulate melanocytes to produce melanin [4]. In some cases, PCSCC may be the malignant progression of a pigmented actinic keratosis or a pigmented Bowen’s disease [4]. The clinical appearance of PCSCC is considered non- specific, with differential diagnoses including other benign and malignant skin lesions such as melanoacanthoma, sebor- rheic keratosis, melanoma, pigmented basal cell carcinoma, pigmented basosquamous carcinoma and pigmented adnexal tumors [3,5]. The dermatoscopic features of our case were unspecific and no algorithm was useful for a correct diagnosis [6,7]. As previously reported by Rosendahl and colleagues, malig- nancy was considered on the basis of the “chaos and clues” algorithm: there was “chaos” (asymmetry, structureless global pattern) and the clues of “few discrete blue-grey blotches with rather ill-defined edges (blue)” and “atypical vessels” [6,7]. Indeed, the scaly center and the pink-white halo were suggestive of a keratotic lesion, even though the diagnosis of PCSCC was not initially considered. On the basis of our and previous reports, PCSCC should be considered when dealing with a pigmented lesion charac- terized by an unspecific dermoscopic pattern with the features of diffuse blue-gray pigmentation, scaling, polymorphic ves- sels and radial structures [1,6,8,9]. Congratulations to Dr. Paschal Dsouza, who was the first to send us the correct answer! References 1. Yoshida Y, Yamasaki A, Shiomi T, et al. Ulcerative pigmented squamous cell carcinoma in a 101-year-old Japanese woman. J Dermatol. 2009;36(4):241-4. 2. Vargas TJ, Campos CM, Coutinho RB. Case for diagnosis: pig- mented squamous cell carcinoma. [Article in Portuguese.] An Bras Dermatol. 2009;84(3):293-5. An atypical pigmented lesion on the nose—Answer Francesco Savoia1, Giuseppe Gaddoni1, Vincenzo Albano1, Vera Tengattini2, Lorenza Ricci2, Annalisa Patrizi2, Emilia Crisanti3 1 Unit of Dermatology, AUSL Ravenna, Italy 2 Department of Specialized, Diagnostic and Experimental Medicine, Division of Dermatology, University of Bologna, Italy 3 Unit of Pathologic Anatomy, AUSL Ravenna, Italy Citation: Savoia F, Gaddoni G, Albano V, Tengattini V, Ricci L, Patrizi A, Crisanti E. An atypical pigmented lesion on the nose—Answer. Dermatol Pract Concept. 2014;4(1):12. http://dx.doi.org/10.5826/dpc.0402a14 Copyright: ©2014 Savoia 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. Corresponding author: Dr. Vera Tengattini, Department of Specialized, Diagnostic and Experimental Medicine, Division of Dermatology, University of Bologna, Via Massarenti, 1, 40138 Bologna, Italy. Tel. +390516364198; Fax. +390516363091. Email: vera.tengattini@ hotmail.com 68 Quiz | Dermatol Pract Concept 2014;4(2):14 3. Satter EK. Pigmented squamous cell carcinoma. Am J Dermatopa- thol. 2007;29(5):486-9. 4. Terada T, Yamagami J, Fugimoto A, Tanaka K, Sugiura M. Pig- mented squamous cell carcinoma of the cheek skin probably arising from solar keratosis. Pathol Int. 2003;53(7):468-72. 5. Giacomel J, Lallas A, Argenziano G, et al. Dermoscopy of baso- squamous carcinoma. Br J Dermatol. 2013;169(2):358-64. 6. Rosendahl C, Cameron A, Bulinska A, Weedon D. Cutaneous pigmented invasive squamous cell carcinoma: a case report with dermatoscopy and histology. Dermatol Pract Concept. 2011;1(1):7. 7. Rosendahl C, Tschandl P, Cameron A, Kittler H. Diagnostic ac- curacy of dermatoscopy for melanocytic and nonmelanocytic pigmented lesions. J Am Acad Dermatol. 2011;64(6):1068-73. 8. Zalaudek I, Citarella L, Soyer HP, Hofmann-Wellenhof R, Ar- genziano G. Dermoscopy features of pigmented squamous cell carcinoma: a case report. Dermatol Surg. 2004;30(4 Pt 1):539-40. 9. De Giorgi V, Alfaioli B, Papi F, et al. Dermoscopy in pigmented squamous cell carcinoma. J Cutan Med Surg. 2009;13(6):326-9.