An apparatus for rapid and continuous processing of tissue specimens up to 3 mm in thickness for histology, the apparatus comprising: (a) a microwave processor unit comprised of (i) a first vessel comprising a first plurality of trays for receiving tissue cassettes for contacting tissue specimens with a non-aqueous solution that fixes, dehydrates, and defats the tissue specimens; (ii) means for agitating the tissue specimens and the non-aqueous solution; (iii) a microwave energy source suitable for exposing the tissue specimens and the non-aqueous solution in the first vessel to microwave energy to achieve uniform heating; (iv) a non-aqueous solution source which is fluidly coupled to the first vessel; wherein (v) the non-aqueous solution, which is comprised of an alcohol and a ketone, and (b) an impregnator unit which is comprised of (i) a second vessel comprising a second plurality of trays for receiving tissue cassettes for containing tissue specimens with a wax solution that impregnates the fixed, dehydrated, and defatted tissue specimens; (ii) a means for agitating the fixed, dehydrated, and defatted tissue specimens and the wax solution in the second vessel; (iii) a vacuum source suitable for exposing the fixed, dehydrated, and defatted tissue specimens and the wax solution to elevated temperature under a vacuum to achieve less than atmospheric pressure; (iv) a wax solution source which is fluidly coupled to the second vessel. (a) a microwave processor unit comprised of (i) a first vessel comprising a first plurality of trays for receiving tissue cassettes for contacting tissue specimens with a non-aqueous solution that fixes, dehydrates, and defats the tissue specimens; (ii) means for agitating the tissue specimens and the non-aqueous solution; (iii) a microwave energy source suitable for exposing the tissue specimens and the non-aqueous solution in the first vessel to microwave energy to achieve uniform heating; (iv) a non-aqueous solution source which is fluidly coupled to the first vessel; wherein (v) the non-aqueous solution, which is comprised of an alcohol and a ketone, and (i) a first vessel comprising a first plurality of trays for receiving tissue cassettes for contacting tissue specimens with a non-aqueous solution that fixes, dehydrates, and defats the tissue specimens; (ii) means for agitating the tissue specimens and the non-aqueous solution; (iii) a microwave energy source suitable for exposing the tissue specimens and the non-aqueous solution in the first vessel to microwave energy to achieve uniform heating; (iv) a non-aqueous solution source which is fluidly coupled to the first vessel; wherein (v) the non-aqueous solution, which is comprised of an alcohol and a ketone, and (b) an impregnator unit which is comprised of (i) a second vessel comprising a second plurality of trays for receiving tissue cassettes for containing tissue specimens with a wax solution that impregnates the fixed, dehydrated, and defatted tissue specimens; (ii) a means for agitating the fixed, dehydrated, and defatted tissue specimens and the wax solution in the second vessel; (iii) a vacuum source suitable for exposing the fixed, dehydrated, and defatted tissue specimens and the wax solution to elevated temperature under a vacuum to achieve less than atmospheric pressure; (iv) a wax solution source which is fluidly coupled to the second vessel. (i) a second vessel comprising a second plurality of trays for receiving tissue cassettes for containing tissue specimens with a wax solution that impregnates the fixed, dehydrated, and defatted tissue specimens; (ii) a means for agitating the fixed, dehydrated, and defatted tissue specimens and the wax solution in the second vessel; (iii) a vacuum source suitable for exposing the fixed, dehydrated, and defatted tissue specimens and the wax solution to elevated temperature under a vacuum to achieve less than atmospheric pressure; (iv) a wax solution source which is fluidly coupled to the second vessel.