A biopsy needle arrangement comprising: - a needle sheath having proximal end and a distal end , the needle sheath constituting an elongated, along a first direction (X), hollow tube having a sheath opening at the distal end of the needle sheath , - the sheath opening being delimited by a first sheath opening edge that defines a first plane and a second sheath opening edge that defines a second plane , the first plane and the second plane intersecting with each other at an angle (A) along a first intersection line , - a needle having proximal end and a distal end , the needle comprising an elongated, along the first direction (X), shaft portion configured to fit inside and slide relative to the needle sheath , a tip portion connected to the shaft portion and located at the distal end of the needle , and a cavity formed by the shaft portion and extending in the first direction (X), a second direction (Y) perpendicular to the first direction (X) and a third direction (Z) perpendicular to the first and second directions (X, Y), - the tip portion having a distal tip and a first proximal tip edge that defines a third plane and a second proximal tip edge that defines a fourth plane , the third plane and the fourth plane intersecting with each other at the angle (A) along a second intersection line , wherein: - the needle arrangement is configured to be in a closed state where the first sheath opening edge abuts the first proximal tip edge and the second sheath opening edge abuts the second proximal tip edge and the first intersection line coincides with the second intersection line characterized in that - the sheath opening edges are configured such that the first intersection line avoids passing through the cavity , during relative sliding between the needle shaft portion and the sheath , for all positions of the first intersection line along the first direction (X). - a needle sheath having proximal end and a distal end , the needle sheath constituting an elongated, along a first direction (X), hollow tube having a sheath opening at the distal end of the needle sheath , - the sheath opening being delimited by a first sheath opening edge that defines a first plane and a second sheath opening edge that defines a second plane , the first plane and the second plane intersecting with each other at an angle (A) along a first intersection line , - the sheath opening being delimited by a first sheath opening edge that defines a first plane and a second sheath opening edge that defines a second plane , the first plane and the second plane intersecting with each other at an angle (A) along a first intersection line , - a needle having proximal end and a distal end , the needle comprising an elongated, along the first direction (X), shaft portion configured to fit inside and slide relative to the needle sheath , a tip portion connected to the shaft portion and located at the distal end of the needle , and a cavity formed by the shaft portion and extending in the first direction (X), a second direction (Y) perpendicular to the first direction (X) and a third direction (Z) perpendicular to the first and second directions (X, Y), - the tip portion having a distal tip and a first proximal tip edge that defines a third plane and a second proximal tip edge that defines a fourth plane , the third plane and the fourth plane intersecting with each other at the angle (A) along a second intersection line , - the needle arrangement is configured to be in a closed state where the first sheath opening edge abuts the first proximal tip edge and the second sheath opening edge abuts the second proximal tip edge and the first intersection line coincides with the second intersection line - the sheath opening edges are configured such that the first intersection line avoids passing through the cavity , during relative sliding between the needle shaft portion and the sheath , for all positions of the first intersection line along the first direction (X). <EOS>