Case 5-2 -

Symplastic haemangioma Dr. Eduoardo Calonje

Clinical History Female, 16. Rapidly growing lesion on right calf. Clinical diagnosis: Atypical mole. No evidence of a recurrence one year later. Case 5-2 - Slide 1 Click to view with ImageScope Click to view with a Web-Based Viewer Histological features Silhouette of a polypioid vascular tumour Focal ulceration with fibrin deposition Thick and thin vascular channels in a background of a myxoid, haemorrhagic and inflamed stroma The larger vascular channels have a muscular wall, which focally appear hyalinized Scattered bizarre mono or rarely multinucleated cells within the stroma. These cells display marked nuclear enlargement, hyperchromatism and occasionally, one or more nucleoli Smooth muscle cells in the walls of some vascular channels also appear enlarged with variable, sometimes prominent atypia Occasional mitotic figures including rare atypical forms Endothelial cells lining the vascular channels are plump and somewhat prominent but cytological atypia tends to be mild or absent and mitotitc figures are exceptional. Diagnosis: Symplastic haemangioma Symplastic haemangioma Symplastic haemangioma (SH) is defined as degenerative type pleomorphism of vascular smooth muscle and interstitial cells in a preexisting, often long standing, vascular neoplasm. The underlying pathogenesis has been attributed to be inflammation or hypoxia. Histologically similar lesions have been described as pleomorphic angioleiomyoma, cutaneous angiomyolipoma with pleomorphic changes and bizarre angiomyomas of soft tissue. SH usually involve the extremities and shows histology of either a cirsoid aneurysm or a capillary-type hemangioma. Occasionally, lobular capillary haemangioma (pyogenic granuloma) may show focal degenerative changes but these tend to be within endothelial cells. The characteristic features of SH as nicely illustrated in this case consist of bizarre pleomorphic ovoid or stellate cells within the walls of the vascular channels or in the interstitium. Mitotic figures may be seen, particularly in the stromal cells. Although occasional mitoses are atypical, the number of overall mitoses is usually low. The endothelial cells show only minimal nuclear atypia. Differential diagnosis The differential diagnoses include angiosarcoma (AS) and pleomorphic hyalinising angiectatic tumor (PHAT). AS has an infiltrative growth pattern with involvement of the dermis and subcutis and is characterized by atypical endothelial cells extending between collagen bundles (infiltration of collagen pattern). Multilayering is a frequent feature and mitotic figures are prominent. PHAT can also show a prominent vasculature but it usually arises in the subcutaneous tissue or deeper soft tissues, it is infiltrative and shows clusters of thin-walled dilated vascular channels in a hyalinized stroma and morer numerous oval or spindle-shaped pleomorphic cells with frequent intranuclear inclusions. References Kutzner H, Winzer M, Mentzel T. Symplastic Haemangioma Hautarzt. 2000; 51: 327-331. Goh N, Calonje E. Symplastic hemangioma: report of 2 cases. J Cutan Pathol 2006; in press. Kawagishi N, Kashiwagi T, Ibe M, et al. Pleomorphic angioleiomyoma. Am J Dermatopathol 2000;22:268-71. Lach B, Duncan E, Rippstein P, et al. Primary intracranial pleomorphic angioleiomyoma--a new morphologic variant. An immunohistochemical and electron microscopic study. Cancer 1994;74:1915-20. Martinez JA, Quecedo E, Fortea JM, et al. Pleomorphic angioleiomyoma. Am J Dermatopathol 1996;18:409-12. Rosai J. Pleomorphic angioleiomyoma. Am J Dermatopathol 1997;19:419. Rodriguez-Fernandez A, Caro-Mancilla A. Cutaneous angiomyolipoma with pleomorphic changes. J Am Acad Dermatol 1993; 29:115-6. Carla TG, Filotico R, Filotico M. Bizarre angiomyomas of superficial soft tissues. Pathologica 1991;83:237-42.