Cutaneous Angiolipomatous Hamartoma Nima Amini, MD; Syed Abedi, MD; Silvija P. Gottesman, MD; Thinh Chau, BS; Jacqueline M Junkins-Hopkins,MD Departments of Pathology & Laboratory Medicine and Dermatology, University of California Davis, Sacramento, CA Ackerman Academy of Dermatopathology, New York, NY

However, only anatomic structures were Introduction immunoreactive to AE1/AE3. A benign Cutaneous vascular anomalies are hamartomatous vascular neoplasm classified as follows: hamartomas, composed of blood vessels and adipose malformations, dilatations of pre-existing tissue was ultimately favored. vessels, hyperplasias, or neoplasms (benign or malignant). Hamartoma is Discussion defined as a disorganized arrangement of tissues indigenous to an organ. Cutaneous The main challenge of this unique case is vascular hamartomas are rare, and include that certain histologic features fit those of a phakomatosis pigmentovascularis (co- hamartomatous vascular entity whereas existence of capillary malformation and others resemble those of a vascular melanocytic lesion) and eccrine neoplasm. Hamartomas encompass several angiomatous hamartoma (EAH), which is a Figure 1. Histopathology of the left temple lesion on H&E stain Figure 2. Overlapping histologic features of a hamartoma and a combined vascular and melanocytic (20X) vascular neoplasm were observed on H&E stain (40X) dermal proliferation of eccrine glands and proliferations, grouped as phakomatosis thin-walled blood vessels, usually noted at pigmentovascularis and so-called eccrine birth or during infancy. PTEN hamartoma of CD10 angiomatous hamartoma which exhibits both soft tissue (PHOST) is a distinctive lesion, eccrine and vascular proliferations. usually intramuscular or subcuticular, in Eccrine angiomatous hamartoma (EAH), a patients with PTEN hamartomatous tumor rare cutaneous hamartoma, share similar syndrome (PHTS). PHTS is characterized histologic features to our case. However, our by hamartomatous elements of adipose lesion is distinct based on late clinical onset, tissue and vessels, predominantly with a absent eccrine proliferation and smooth fibromyxoid stroma and occasionally other muscle bundles, and prominent elements (lymphoid follicles, neural tissue, subcutaneous extension. Multiple lesions are and bone). We report a case of a typical in patients with EAH whereas our hamartomatous-appearing vascular lesion, patient presented with a solitary lesion. which does not fulfill histologic criteria for the aforementioned entities. Figure 3. Overlapping histologic features of a hamartoma and a Figure 4. Histopathology of the lesion with vessels and adipose Although our case bears histologic vascular neoplasm were observed on H&E stain (100X) tissue on H&E stain (100X) resemblance to PHOST, a fibromyxoid Case History stroma was absent in our case. The TryptaseMNF116 occasional lymphoid follicles, neural tissue A 70-year-old man presented with a 2-year and bone were not also observed. history of a 1.5cm cystic lesion on the left temple. Histologically, there were variably Immunohistochemical studies were crucial to dilated thick-walled blood vessels intimately distinguishing this new entity from previously associated with smaller vessels and discussed conditions. AE1/AE3 highlighted a adipocytes in the dermis and subcutis, with pattern favoring entrapped anatomic eccrine entrapment of anatomic eccrine glands. glands in contrast to eccrine proliferation, a (Figure 1, 4) Immunostain against CD31 characteristic feature of EAH. and SMA highlighted well-formed vessels; References 1.Requena L, Sangueza OP. Cutaneous vascular anomalies. smooth muscle bundles were absent. No Part I. Hamartomas, malformations, and dilation of preexisting distinct spindle cell component was vessels. Journal of American Academy of Dermatology. 1997 highlighted by SMA staining. Scattered October;37(4):523-49; quiz 549-52. eccrine glands were seen. Figure 5. Entrapped eccrine glands (200X) Contact info: [email protected]