Symplastic hemangiomaD18.01

Tsang et al.1994

Benign, solid , superficial tumor of variable size that is clinically recognized as a vascular tumor.

Unspectacular clinical aspect. Resembles a capillary angioma of the skin. Systemic organ involvement has been documented (Bantan NAA et al. 2021). Of note, evidence of a symplastic hemangioma over an infant hemangioma treated with propanolol (Downey C et al. 2019).

Thick-walled, variably dilated vessels with conspicuous pleomorphic myoid vessel wall cells with nuclear hyperchromasia of the endothelia, without multilayering or mitoses, are conspicuous (Goh SG et al. 2006). Furthermore, bizarre hyperchromatic stromal fibroblasts are found. IN the fibrous to edematous stroma, hemosiderin deposits may be found as well as a mononuclear inflammatory infiltrate.

Immunohistochemistry showed focal smooth muscle actin positivity in the pleomorphic cells of the vessel walls. The stromal cells stained positively with CD68 and CD34. The bizarre cytologic changes are interpreted as degenerative and probably resemble those seen in old schwannomas and symplastic leiomyomas.

The tumor is benign. No tendency to recurrence after surgery. No metastases known.

The term "symplast" originally referred to multinucleated cells of smooth muscle tumors. In the meantime, however, the term is used for a variety of mesenchymal tumors of mostly benign dignity.

1. Bantan NAA et al (2021) A unique case of multiple calvarial hemangiomas with one large symplastic hemangioma. BMC Neurol 21:29.
2. Downey C et al. (2019) Symplastic hemangioma developing over an infantile hemangioma during propranolol treatment. Pediatr Dermatol 36:961-962.
3. Goh SG et al (2006) Symplastic hemangioma: report of two cases. J Cutan Pathol 33:735-740.
4. Kutzner H et al (2000) Symplastic hemangioma [Symplastic hemangioma]. Dermatologist 51:327-331.
5. Tsang W et al (1994) Symplastic hemangioma: a distinctive vascular neoplasm featuring bizarre stromal cells. Int J Surg Pathol1:202.