Terahertz　waves　provide　a　better　contrast　in　imaging　soft　biomedical　tissues　than　X-rays,　and　unlike　X-rays,　they　cause　no　ionisation　damage,　making　them　a　good　option　for　biomedical　imaging.　Terahertz　absorption　imaging　has　conventionally　been　used　for　cancer　diagnosis.　However,　the　absorption　properties　of　a　cancerous　sample　are　influenced　by　two　opposing　factors:　an　increase　in　absorption　due　to　a　higher　degree　of　hydration　and　a　decrease　in　absorption　due　to　structural　changes.　It　is　therefore　difficult　to　diagnose　cancer　from　an　absorption　image.　Phase　imaging　can　thus　be　critical　for　diagnostics.　We　demonstrate　imaging　of　the　absorption　and　phase-shift　distributions　of　3.2　mm　x　2.3　mm　x　30-mu　m-thick　human　hepatocellular　carcinoma　tissue　by　continuous-wave　terahertz　digital　in-line　holography.　The　acquisition　time　of　a　few　seconds　for　a　single　in-line　hologram　is　much　shorter　than　that　of　other　terahertz　diagnostic　techniques,　and　future　detectors　will　allow　acquisition　of　meaningful　holograms　without　sample　dehydration.　The　resolution　of　the　reconstructions　was　enhanced　by　sub-pixel　shifting　and　extrapolation.　Another　advantage　of　this　technique　is　its　relaxed　minimal　sample　size　limitation.　The　fibrosis　indicated　in　the　phase　distribution　demonstrates　the　potential　of　terahertz　holographic　imaging　to　obtain　a　more　objective,　early　diagnosis　of　cancer.