In this work, we introduce a high speed and area efficient Cellular Nonlinear Network (CNN) cell, featuring two circuit variants that utilize threshold switches. The threshold switch (TS) model employed represents a current-controlled nanoscale negative differential resistance (NDR) device which exhibits an S-shaped DC I-V curve as a fingerprint. The proposed cell can be considered as the dual of the standard isolated CNN cell where the bistable cell characteristics, originating from the N-shaped voltage-controlled resistor, is implemented through the S-shaped current-controlled TSs. Similarly, the dynamics induced by the parallel capacitor accompanying the nonlinear resistor in the standard cell version are implemented through the internal inductive dynamics of the TSs, resulting in area and speed efficiency. The proposed CNN cell employs a DC voltage source, two bias resistors and 2 TSs, and essentially, features a differential-mode operation which helps to endow it with a symmetric DC I-V characteristic, as is the case for the standard CNN cell. The differential-mode approach further introduces design flexibility as the cell DC I-V characteristic can be adjusted by tuning circuit parameters. We demonstrate the functionality of the proposed cell by implementing image processing tasks ranging from edge detection and thresholding to logic AND and OR operations.