1. A method to effectively discriminate between having a malignant lung lesion and not having a malignant lung lesion in a medical patient, comprising: providing a measurement device operable to measure conductivity between a reference point and an interrogation point on the body of a medical patient having an indeterminate lung lesion, wherein the measurement device is configured to provide control of contact pressure between a measurement electrode tip and the surface of the body of the patient; measuring the conductivity between a plurality of reference points and a plurality of interrogation points with the measurement device by administering sufficient pressure between the measurement electrode tip and the surface of the body of the patient until a plot of a conductivity index over time exhibits a slope at or near zero, to obtain at least one patient data set comprising a plurality of conductivity curves having a plurality of curve attribute values; and comparing a plurality of curve attribute values obtained from the at least one patient data set to a plurality of corresponding curve attribute values in a previously-determined corresponding data set obtained using a similar measuring step; wherein the previously-determined corresponding data set was determined by comparing, from a population of patients having lung lesions, (i) a first cohort having malignant lung lesions and (ii) a second cohort having benign lung lesions, the malignant lung lesions of the previously-determined corresponding data set being determined by examination of lesion biopsies, to obtain a data set that effectively discriminates between the cohort having malignant lung lesions and the cohort having benign lung lesions, to thereby determine the likelihood of the patient having a malignant lung lesion.