BACKGROUND Histopathological findings in biopsy specimens from patients with cutaneous small-vessel vasculitis (CSVV) secondary to solid-organ malignancy have not been previously reported. OBJECTIVE We aimed to understand better the differences in histopathological findings between biopsy specimens from patients with CSVV associated with solid-organ malignancies and patients with CSVV secondary to other causes. METHODS From a previously published group of patients with CSVV and solid-organ malignancy, we identified patients with available histopathology slides of biopsy specimens. We compared histopathological findings from these patients with those from 68 previously published patients with Henoch-Schönlein purpura not associated with solid-organ malignancy (60% male). RESULTS We identified 15 patients (eight male, 53%) with available slides from biopsy specimens. The mean age of these patients with solid-organ malignancy-associated CSVV was 66·6 years, compared with 45·8 years in the Henoch-Schönlein purpura cases not associated with solid-organ malignancy (P < 0·001). Solid-organ malignancy-associated CSVV was less likely to demonstrate papillary dermal oedema (P = 0·04), papillary dermal inflammation (P < 0·001) and lymphocytes (P < 0·001), and more likely to have plasma cells (P = 0·02). Additionally, we detected nonsignificant differences in the presence of histiocytes (P = 0·05), intravascular thrombosis (P = 0·052) and microabscess formation (P = 0·06). CONCLUSIONS CSVV associated with solid-organ malignancies tended to have deeper dermal involvement and a different cellular milieu from cases not associated with solid-organ malignancies. In addition, the patients with CSVV with solid-organ malignancies were significantly older than those without. Prospective studies with age-matched controls are needed to determine the clinical significance of the histopathological differences in solid-organ malignancy-associated CSVV.