Dermatology: Practical and Conceptual Quiz | Dermatol Pract Concept 2016;6(1):2 3 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com The patient A 44-year-old Caucasian woman presented with asymptom- atic skin lesions on the trunk, arms and legs. These lesions had suddenly appeared 4 months before and have been unchanged ever since. Medical history included arterial hypertension and hypertriglyceridemia. The patient recalled an acute episode of painful subcutaneous nodules on the lower legs some years ago that disappeared with NSAID and leg rest. On physical examination, we observed a bilateral and symmetric dermatosis composed of multiple well-defined erythematous papules and plaques involving the trunk, arms and legs, and sparing the face, acral sites and mucosae. Some of the papules appeared to be pseudovesicular with a yellow- ish hue (Figure 1). Further dermoscopic examination disclosed multiple orange and yellowish globules and structureless areas in combination with linear vessels (Figure 2). A 4 mm punch biopsy was performed. Histopathological examination revealed an unchanged epidermis and organized collections of epithelioid histiocytes on the superficial and deep dermis (Figures 3 and 4). Underneath the “apple-jelly” Pedro Mendes-Bastos1, André Oliveira1, Cândida Fernandes1 1Department of Dermatology and Venereology, Centro Hospitalar de Lisboa Central, Lisboa, Portugal Citation: Mendes-Bastos P, Oliveira A, Fernandes C. Underneath the “apple-jelly.” Dermatol Pract Concept 2016;6(1):2. doi: 10.5826/ dpc.0601a02 Received: September 4, 2015; Accepted: October 16, 2015; Published: January 31, 2016 Copyright: ©2016 Mendes-Bastos 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: Pedro Mendes-Bastos, MD, Department of Dermatology and Venereology, Alameda de Santo António dos Capuchos, 1169-050 Lisboa, Portugal. Tel. +351213136380; Fax. +351213136380. Email: pmendesbastos@gmail.com Figure 1. Disseminated papules and plaques on the trunk, arms and legs. [Copyright: ©2016 Mendes-Bastos et al.] Figure 2. Multiple orange-yellowish structureless areas (surrounded by asterisks) and linear vessels in a yellow-tone background. [Copy- right: ©2016 Mendes-Bastos et al.] 4 Quiz | Dermatol Pract Concept 2016;6(1):2 included secondary syphilis, eruptive xanthomas and cutane- ous lymphoma. The term inflammoscopy has been introduced to describe the use of dermoscopy in the diagnosis of inflammatory skin diseases [2]. The combination of orange and yellow translu- cent globules and linear vessels is commonly seen under der- moscopy in granulomatous diseases. These structures correlate well with the underlying dermal granulomas. Thus, they are frequently found in cutaneous sarcoidosis and lupus vulgaris, probably mirroring the classically described “apple-jelly” sign observed upon diascopy. Therefore, under appropriate clinical correlation, dermoscopy can be a valuable non-invasive tool for the diagnosis of cutaneous sarcoidosis [3]. References 1. Tchernev G. Cutaneous sarcoidosis: the “great imitator”: etio- pathogenesis, morphology, differential diagnosis and clinical management. Am J Clin Dermatol. 2006;7:375-82. 2. Zalaudek I, Lallas A, Moscarella E, et al. The dermatologist’s stethoscope—traditional and new applications of dermoscopy. Dermatol Pract Concept. 2013;3(2):11. doi: 10.5826/dpc.0302a11 3. Lallas A, Zalaudek I, Argenziano G, et al. Dermoscopy in general dermatology. Dermatol Clin. 2013;31:679-94. No necrosis or other inflammatory infiltrate were ob- served. Periodic acid-Schiff (PAS), Grocott and Ziehl-Neelsen stains were unremarkable. What is your diagnosis? Diagnosis Cutaneous sarcoidosis Clinical course Chest CT revealed bilateral hilar lymphadenopathy. The patient was referred to pulmonology, and Stage I sarcoidosis was diagnosed. Answer and explanation Sarcoidosis is an idiopathic multisystemic granulomatous disease that mostly involves the lung, lymph nodes, eyes and skin. Cutaneous involvement is seen in 25% of patients. Specific skin lesions of sarcoidosis are highly polymorphous and establishing a correct diagnosis is frequently a challenge [1]. In this particular case, the clinical differential diagnoses Figure 3. Unchanged epidermis and a dermal granulomatous derma- titis. [Copyright: ©2016 Mendes-Bastos et al.] Figure 4. Organized collections of epithelioid histiocytes on the su- perficial and deep dermis, with scattered multinucleated giant cells. [Copyright: ©2016 Mendes-Bastos et al.] Quiz | Dermatol Pract Concept 2016;6(1):2 5