Aims: To investigate and define a morphologically distinctive group of cutaneous papillary haemangiomas.
Methods and results: Eleven patients (seven male, four female, age range 1-77 years, median 57) were identified with a solitary bluish cutaneous papule (median size 11 mm) arising in the head and neck region. Most lesions had been present for several years. None of the patients had associated systemic disease or polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome. Only one lesion recurred locally. The lesions showed predominantly intravascular papillary growth within multiple ectatic dermal vessels. The papillae had cellular cores containing pericytes and stromal cells, arranged around normal small capillaries. The surfaces of the papillae were covered by focally swollen endothelial cells containing numerous hyaline globules, ultrastructurally representing giant lysosomes containing organelle debris and fat vacuoles (so-called thanatosomes). These endothelial cells were immunopositive for CD31 and CD34 but negative for D2-40 (podoplanin).
Conclusions: Papillary haemangioma is a distinctive benign cutaneous lesion containing eosinophilic hyaline globules consistent with dysfunction of the autophagocytic-lysosomal pathway.