UNITED STATES SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange
Act of 1934

December 24, 2002
------------------
(Date of earliest event reported)


LABORATORY CORPORATION OF AMERICA HOLDINGS
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(Exact name of registrant as specified in its charter)


   DELAWARE                1-11353             13-3757370
 --------------          -----------         --------------
(State or other         (Commission          (IRS Employer
jurisdiction of         File Number)         Identification
incorporation)                                   Number)


358 SOUTH MAIN STREET, BURLINGTON, NORTH CAROLINA 27215
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(Address of principal executive offices)

336-229-1127
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(Registrant's telephone number, including area code)


ITEM 9. Regulation FD Disclosure.

Laboratory Corporation of America-Registered Trademark-
Holdings (LabCorp-Registered Trademark-) (NYSE: LH) and
Dianon Systems, Inc. (Nasdaq:DIAN) today announced that the
waiting period under the Hart-Scott-Rodino Antitrust
Improvements Act with respect to LabCorp's proposed
acquisition of DIANON expired at 11:59 PM, New York City
time, on December 23, 2002.

This transaction remains subject to various conditions
including approval by the stockholders of DIANON at a
meeting scheduled to be held January 17, 2003.  LabCorp
continues to expect that this transaction will close in the
first quarter of 2003.



The first national clinical laboratory to fully embrace
genomic testing, Laboratory Corporation of America-
Registered Trademark- Holdings (LabCorp-Registered
Trademark-) has been a pioneer in commercializing new
diagnostic technologies.  As a national laboratory with
annual revenues of $2.2 billion in 2001 and over 25,000
employees, the Company offers more than 4,000 clinical tests
ranging from routine blood analyses to sophisticated
molecular diagnostics.  Serving more than 200,000 clients
nationwide, LabCorp combines its expertise in innovative
clinical testing technology with its Centers of Excellence.
The Center for Molecular Biology and Pathology, in Research
Triangle Park, North Carolina, offers state-of-the-art
molecular gene-based testing in infectious disease, oncology
and genetics. Its National Genetics Institute in Los Angeles
is an industry leader in developing novel, highly sensitive
polymerase chain reaction (PCR) methods for testing
hepatitis C and other blood borne infectious agents.
LabCorp's Minneapolis-based ViroMed offers molecular
microbial testing using real time PCR platforms, while its
Center for Esoteric Testing in Burlington, North Carolina,
performs the largest volume of specialty testing in the
network.  LabCorp's clients include physicians, state and
federal governments, managed care organizations, hospitals,
clinics, pharmaceutical and Fortune 1000 companies, and
other clinical laboratories.

DIANON provides a full line of anatomic and molecular
pathology testing services and the CarePath-trademark-
Health Information Service, which provides personalized,
diagnosis-specific information to physicians and their
patients at critical moments in the healthcare process.
DIANON has more than 650 managed care contracts and over
14,500 physician customers use DIANON's services, including
5,000 of the country's 7,500 urologists.  The Company has
labs in Connecticut, New York, Florida, Texas and Oklahoma,
along with a centralized specimen processing center in Ohio.
Further information about DIANON can be obtained from the
Company's web sites at www.DIANON.com or
www.carepathonline.com.

Each of the above forward-looking statements is subject to
change based on various important factors, including without
limitation, competitive actions in the marketplace and
adverse actions of governmental and other third-party
payors.  Actual results could differ materially from those
suggested by these forward-looking statements.  Further
information on potential factors that could affect LabCorp's
or DIANON's financial results is included in each Company's
Form 10-K for the year ended December 31, 2001 and
subsequent SEC filings.



DIANON has filed a proxy statement and DIANON and LabCorp
will file other relevant documents with the SEC concerning
the proposed merger of a wholly-owned subsidiary of LabCorp
with and into DIANON. INVESTORS ARE URGED TO READ THE PROXY
STATEMENT AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE
SEC BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. You may
obtain the documents free of charge at the website
maintained by the SEC at www.sec.gov. In addition, you may
obtain documents filed with the SEC by LabCorp free of
charge by requesting them in writing from LabCorp at 430
South Spring Street, 1st Floor, Burlington, North Carolina
27215, Attention:  Investor Relations, or by telephone at
(336) 229-1127.  You may obtain documents filed with the SEC
by DIANON free of charge by requesting them in writing from
DIANON, 200 Watson Boulevard, Stratford, Connecticut 06615,
Attention: Secretary, or by telephone at (203) 381-4055.

LabCorp and DIANON, and their respective directors and
executive officers, may be deemed to be participants in the
solicitation of proxies from the stockholders of DIANON in
connection with the merger. Information about the directors
and executive officers of LabCorp and their ownership of
LabCorp shares is set forth in the proxy statement for
LabCorp's 2001 annual meeting of shareholders filed with the
SEC on April 15, 2002. Information about the directors and
executive officers of DIANON and their ownership of DIANON
stock is set forth in the proxy statement for DIANON's 2002
annual meeting of stockholders filed with the SEC on July 1,
2002. Investors may obtain additional information regarding
the interests of such participants by reading the proxy
statement when it becomes available.



SIGNATURES

Pursuant to the requirements of the Securities and Exchange
Act of 1934, the registrant has duly caused this report to
be signed on its behalf by the undersigned hereunto duly
authorized.

          LABORATORY CORPORATION OF AMERICA HOLDINGS
          ------------------------------------------
                        (Registrant)

               By:/s/ BRADFORD T. SMITH
                  ----------------------------------
                      Bradford T. Smith
                      Executive Vice President
                      and Secretary



Date: December 24, 2002