DAVID C. BUPP 5747 RUSHWOOD DRIVE DUBLIN, OHIO 43017 February 16, 1999

   1
                                                                 Exhibit 10.2.46

                                  XXXXX X. XXXX
                               0000 XXXXXXXX XXXXX
                               XXXXXX, XXXX 00000


                                February 16, 1999



Paramount Capital Asset Management, Inc.
Attn: Xxxxxxx X. Xxxxxxxxx, M.D.
Chairman
000 Xxxxxxx Xxxxxx
Xxx Xxxx XX  00000

RE:  PREFERRED STOCK AND WARRANT PURCHASE AGREEMENT (THE "PURCHASE
     AGREEMENT) DATED AS OF FEBRUARY 16, 1999 BY AND AMONG NEOPROBE
     CORPORATION, A DELAWARE CORPORATION (THE "COMPANY") AND THE
     PURCHASERS LISTED ON EXHIBIT A TO THE PURCHASE AGREEMENT (THE
     "PURCHASERS").

Dear Xx. Xxxxxxxxx:

     Reference is made to the Employment Agreement dated as of January 1, 1998
between the Company and me (the "Employment Agreement"). In order to induce the
Purchasers to enter into the Purchase Agreement and to purchase the 5% Series B
Convertible Preferred Stock (the "Preferred Stock") issuable thereunder, which I
hereby acknowledge is a direct and material benefit to me, I hereby waive and
relinquish any claim that I am entitled to receive a severance payment under the
first sentence in paragraph H of Section 3 of the Employment Agreement solely by
reason of the issuance of the Preferred Stock or the warrants issued to the
Purchasers thereof, or to Paramount Capital, Inc. pursuant to the Purchase
Agreement (the "Warrants") or the conversion of the Preferred Stock into the
Company's Common Stock or the exercise of the Warrants to purchase Common Stock
or Preferred Stock by the persons who acquired the Preferred Stock and the
Warrants, pursuant to the Purchase Agreement.

                                                     Very truly yours,

                                                     /s/ Xxxxx X. Xxxx

                                                     Xxxxx X. Xxxx