VAS ABERRANS OF HALLER : a blind tube that is occasionally present parallel to the first part of the vas deferens and that may communicate with the vas deferens or with the epididymis—called also ductulus aberrans

Internal medicine

Empyema necessitatis
the spontaneous extension of pus through the
parietal pleura and chest wall from an empyema with
the formation of a subcutaneous abscess. In most
circumstances this occurs secondary to a tuberculous
empyema. There may be an associated bronchopleural
fistula. CT is used to demonstrate the empyema and
its extension through the chest wall and associated
bronchopleural fistula.