Dermatology: Practical and Conceptual DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Observation | Dermatol Pract Concept 2013;3(4):3 11 Introduction Hemangioendothelioma is a term encompassing neoplasms with an intermediate biological behavior between benign hemangiomas and angiosarcomas. It affects the skin and the soft tissues and includes retiform hemangioendothelioma (RH), papillary intralymphatic angioendothelioma (PILA, Dabska’s tumor), epithelioid, kaposiform, pseudomyogenic, and composite hemangioendotheliomas [1]. RH is an infrequently encountered vascular neoplasm of borderline malignancy that was originally classified as a distinct type of low-grade cutaneous angiosarcoma (CA) in 1994 by Calonje et al [2]. Histopathologically, the vascular channels of RH resemble the rete testis (retiform), while the term “hemangioendothelioma” reflects its putative border- line malignancy, as opposed to the benign angioma and the malignant angiosarcoma. Morphologically, RH typically develops as a solitary, gradually enlarging exophytic mass, nodule or plaque, most often on the lower limbs, upper limbs and trunk. The tumor shows a predilection for young to middle-aged adults (mean age 36 years) and females (2:1) [2]. Duration of the disease and tumor size at the time of diagnosis have been reported to range from 2 months to several years and from 1 to 30 cm, respectively [2]. A case of RH presenting with multiple lesions on the limbs and trunk has also been described [3]. Surgical excision is the treatment of choice for RH [1-4]. However, accurately defining the excision margins in a vascu- Clinical, dermoscopic and histopathologic findings of retiform hemangioendothelioma Amanda Mota1, Giuseppe Argenziano1, Iris Zalaudek1,2, Simonetta Piana1, Caterina Longo1, Elvira Moscarella1, Aimilios Lallas1 1 Skin Cancer Unit, Arcispedale Santa Maria Nuova IRCCS, Reggio Emilia, Italy 2 Department of Dermatology, Medical University of Graz, Austria Key words: retiform hemangioendothelioma, hemangioendothelioma, dermoscopy, vascular tumors Citation: Mota A, Argenziano G, Zalaudek I, Piana S, Longong C, Moscarella E, Lallas A. Clinical, dermoscopic and histopathologic findings of retiform hemangioendothelioma. Dermatol Pract Conc. 2013;3(4):3. http://dx.doi.org/10.5826/dpc.0304a03. Received: June 20, 2013; Accepted: July 9, 2013; Published: October 31, 2013 Copyright: ©2013 Mota 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: This study was supported, in part, by the Italian Ministry of Health (RF-2010-2316524. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Aimilios Lallas, M.D., Skin Cancer Unit, Arcispedale Santa Maria Nuova, Viale Risorgimento 80, 42123 Reggio Emilia, Italy. Tel. 00390522295611; Fax. 00390697625822. Email: emlallas@gmail.com Retiform hemangioendothelioma (RH) is an uncommon vascular neoplasm of borderline malignancy that clinically develops as a solitary, gradually enlarging exophytic mass, nodule or plaque, most often on the lower limbs, upper limbs and trunk. Clinical recognition of RH is troublesome because of its non-specific appearance, with differential diagnosis comprising a variety of benign and malignant tu- mors clinically presenting as reddish nodules. In this article we describe the clinical, dermoscopic and histopathologic findings in a case of RH developing on the flank of a 26-year-old woman, and discuss the possible role of dermoscopy in facilitating the clinical recognition of this rare tumor. ABSTRACT 12 Observation | Dermatol Pract Concept 2013;3(4):3 quently excised. On histopathology, some residual dissecting vessels were present besides the dermal scar. Discussion Clinical recognition of RH is troublesome because of its non- specific appearance, with differential diagnosis comprising a variety of benign and malignant tumors clinically presenting as reddish nodules. RH has to be differentiated from other hemangioendotheliomas, CA, hemangioma, targetoid hemo- siderotic hemangioma, blue-rubber bleb nevus syndrome, Kaposi’s sarcoma (KS), lymphoma, dermatofibrosarcoma protuberans, amelanotic melanoma (AM) and cutaneous metastases [2,3]. Although the diagnosis of RH is based on histopathologic examination, discrimination from other vascular tumors might be challenging even histopathologically. The presence of infiltrative vascular spaces allows ruling out benign pro- liferations as hobnail hemangioma, which typically is more superficial and well defined. Differentiation from Kaposi’s sarcoma (KS) is based mainly on the different clinical set- ting, the typical cellular spindling and the HHV8 immuno- reactivity of the neoplastic cells that characterize KS. CA is characterized by cellular pleomorphism and prominent mitotic activity, features that allow discrimination from RH. Distinguishing between RH and PILA is highly challenging, since they both affect young patients, are characterized by a predilection for the limbs, and share similar histopathologic characteristics [5-7]. The architecture of the vessels, which are thin and arborizing in RH and often dilated in PILA, and the immunohistochemical reactivity of the latter to markers of lymphatic differentiation like D2-40 and VEGFR-3 represent clues for differentiating between the two entities [7]. In our case, D2-40 antibody reacted only in normal vascular endothelium, representing the internal control, and lar neoplasm with a dissecting growth pattern is particularly troublesome. Indeed, the tumor is associated with a high rate of local recurrence (50%), which may occur from months to several years after surgery [2,3]. Regional lymph node metastasis was reported in a single patient, while no distant metastases have been reported to date [4]. Case report A 26-year-old woman presented with a 2-month history of an asymptomatic, enlarging tumor of the right flank. The patient’s previous medical history was unremarkable. Clinical examination revealed a well-defined, infiltrated red nodule, measuring a diameter of 3 cm (Figure 1). No regional lymph- adenopathy was detected. Dermoscopic examination revealed a pinkish background color and few dotted and linear vessels (Figure 2). Histopathologic examination (Figures 3 and 4) following punch biopsy revealed that the tumor was dermal based and ill defined. It was characterized by an infiltrative growth pat- tern, involving the entire dermis but sparing the subcutis, and consisted of long and thin arborizing vessels dissecting the dermal collagen. The vessels were lined by plump endothelial cells with frequent hobnail features and papillary projections. Rare solid endothelial areas were present in the superficial part of the lesion. No cytological atypia nor mitotic activity were noted. Extravasation of erythrocytes, hemosiderin depo- sition and inflammatory infiltrate were absent. On immuno- histochemistry, the lesion reacted diffusely with CD31 and focally with D2-40. The monoclonal antibody against the latent nuclear antigen-1 of HHV8 was negative. Based on the aforementioned histopathologic findings, the diagnosis of RH was established and the tumor was subse- Figure 1. An asymptomatic, rapidly enlarging, infiltrated, red nod- ule. [Copyright: ©2013 Mota et al.] Figure 2. Dermoscopically, the tumor exhibited a pinkish back- ground colour and few dotted and linear vessels. [Copyright: ©2013 Mota et al.] Observation | Dermatol Pract Concept 2013;3(4):3 13 Figure 3. (A) At low magnification, the neoplasm was ill defined and in- volved the entire dermis (H&E x20). (B) A higher magnification revealed that it consisted of long arborizing vessels, dissecting the dermal collagen (H&E x100). (C) The vessels were lined by plump endothelial cells with frequent papillary projections (H&E x200). [Copyright: ©2013 Mota et al.] Figure 4. (A) Few solid areas were present in the upper dermis (H&E x100). (B) In the lower dermis, the neoplastic proliferation showed an in- filtrative growth pattern among the collagen bundles (H&E x100). (C) The diffuse immunohistochemical positivity with CD31 confirmed the endothelial origin of the neoplastic proliferation, (D) while antibody D2-40 stained only rare lymphatic vessels. [Copyright: ©2013 Mota et al.] 14 Observation | Dermatol Pract Concept 2013;3(4):3 References 1. Requena L, Kutzner H. Hemangioendothelioma. Semin Diagn Pathol. 2013;30(1):29-44. 2. Calonje E, Fletcher CD, Wilson-Jones E, Rosai J. Retiform he- mangioendothelioma. A distinctive form of low-grade angio- sarcoma delineated in a series of 15 cases. Am J Surg Pathol. 1994;18(2):115-25. 3. Duke D, Dvorak A, Harris TJ, Cohen LM. Multiple retiform hemangioendotheliomas. A low-grade angiosarcoma. Am J Der- matopathol. 1996;18(6):606-10. 4. Bhutoria B, Konar A, Chakrabartis S, Das S. Retiform hemangio- endothelioma with lymph node metastasis: a rare entity. Indian J Dermatol Venereol Leprol. 2009;75(1): 60-2. 5. Fukunaga M, Endo Y, Masui F, et al. Retiform haemangioendothe- lioma. Virchows Arch. 1996:428(4-5):301-4. 6. Dabska M. Malignant endovascular papillary angioendothelioma of the skin in childhood: clinicopathologic study of 6 cases. Can- cer. 1969;24:503-10. 7. Fanburg-Smith JC, Michal M, Partanen TA, Alitalo K, Mietinen M. Papillary intralymphatic angioendothelioma (PILA): a report of twelve cases of a distinctive vascular tumor with phenotypic fea- tures of lymphatic vessels. Am J Surg Pathol. 1999;23(9):1004-10. 8. Emberger M, Laimer M, Steiner H, Zelger B. Retiform hemangio- endothelioma: presentation of a case expressing D2-40. J Cutan Pathol. 2009;36(9):987-90. 9. Parsons A, Sheehan DJ, Sangueza OP. Retiform hemangioendo- theliomas usually do not express D2-40 and VEGFR-3. Am J Dermatopathol. 2008;30:31-3. 10. Zalaudek I, Kreusch J, Giacomel J, et al. How to diagnose non- pigmented skin tumors: a review of vascular structures seen with dermoscopy: part 1. Melanocytic skin tumors. J Am Acad Dermatol. 2010;63(3):361-784. 11. Zalaudek I, Gomez-Moyano E, Landi C, et al. Clinical, dermo- scopic and histopathological features of spontaneous scalp or face and radiotherapy-induced angiosarcoma. Australas J Dermatol. 2013;54(3):201-7. failed to demonstrate a convincing lymphatic differentiation, findings suggestive of the diagnosis of RH [8,9]. Given that the choice treatment of RH is surgical exci- sion to tumor-free margins, the most relevant differential diagnostic problem in clinical terms, is to discriminate RH from benign vascular tumors, whose management is essen- tially conservative. Dermoscopy has been shown to improve the clinical evaluation of pigmented and non-pigmented skin tumors, enabling the visualization of morphologic structures that might be critical for the differential diagnosis [10]. In our case, dermoscopy revealed a pinkish color, which is also known to characterize AM, KS and CA and, effectively, cannot be considered as predictive of a specific diagnosis [10,11]. However, since it has been only described in the con- text of malignant tumors, the detection of pinkish (milky red) color enhanced us to avoid misinterpretation of the tumor as benign and prompted us to perform a biopsy. In conclusion, although the dermoscopic criteria of RH and other endotheliomas require further investigation, our case highlights that dermoscopy should always be performed when clinically evaluating skin tumors, since the additional morphologic information provided might facilitate the appro- priate clinical decision. Undoubtedly, dermoscopic findings should always be integrated with clinical information, such as patient’s age and history. Furthermore, the current case further supports the previously reported observation that detection of pinkish color on dermoscopy of nodular lesions is suggestive of malignancy and should warrant excision. Finally, RH should be added in the differential diagnostic spectrum when evaluat- ing a red nodule exhibiting a pinkish color under dermoscopy.