Cytyc Ranked #5 on Forbes List of Top 100 Mid-Cap Stocks.

MARLBOROUGH, Mass. -- Cytyc Corporation (Nasdaq: CYTC), a leading women's health company, today announced that the Company has been ranked #5 on Forbes Magazine's 2006 list of the 100 Best Mid-Cap Stocks. The prestigious list, published this week, is based on a variety of performance criteria for mid-cap companies - those with market values between $1 and $4 billion. The Special Report noted that "there is still a compelling case for mid-caps, as they offer more room for growth than larger companies and greater safety and stability than smaller companies."

"We are extremely proud to be among the elite companies in this category," said Patrick J. Sullivan, Cytyc's chairman, president and chief executive officer. "Our goal is to become the leading provider of innovative products focused on women's health worldwide. Our ThinPrep(R) Pap Test is the standard of care for cervical screening in the U.S., our NovaSure(R) Endometrial Ablation System is currently the market leader for treating women with abnormal uterine bleeding, and our MammoSite(R) Radiation Therapy System is providing a beneficial alternative for post-lumpectomy radiation therapy for breast cancer patients. We will continue to strive to provide improved patient outcomes as well as strong financial performance."

Forbes arrives at this list by starting with a universe of more than 1,000 mid-cap companies, which it screened for positive return on equity, sales, and earnings-per-share growth over the past five years and through the latest 12 months. Companies were also required to have forecasts for at least 10 percent annualized earnings growth over the next three to five years, according to consensus estimates tabulated by Thomson IBES. Researchers also looked at analyst write-ups, current news, business trends and changes in consensus forecasts, as well as metrics to measure the degree to which past earnings are reliable and are likely to persist. More information about the list can be found on the Forbes Magazine website (www.forbes.com).

Cytyc Corporation is a leading women's health company that designs, develops, manufactures, and markets innovative and clinically effective products for cervical cancer screening, breast cancer risk assessment, treatment of excessive menstrual bleeding, and treatment of breast cancer.

Cytyc is traded on The Nasdaq Stock Market under the symbol CYTC. Cytyc, ThinPrep, NovaSure, and MammoSite are registered trademarks of Cytyc Corporation.

Forward-looking statements in this press release are made pursuant to the provisions of Section 21E of the Securities Exchange Act of 1934. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements relating to Cytyc's future financial condition, operating results and economic performance, and management's expectations regarding key customer relationships, future growth opportunities, product acceptance and business strategy, constitute forward-looking statements. These statements are based on current expectations, forecasts and assumptions that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from those statements. Risks and uncertainties include, among others, dependence on key personnel and customers as well as reliance on proprietary technology, uncertainty of product development efforts and product acceptance, management of growth, product diversification, and organizational change, entry into new market segments domestically and new markets internationally, risks associated with litigation, the effective integration of acquired businesses and technologies, competition and competitive pricing pressures, risks associated with the FDA regulatory approval processes and healthcare reimbursement policies in the United States and abroad, introduction of technologies that are disruptive to Cytyc's business and operations, the impact of new accounting requirements and governmental rules and regulations, as well as other risks detailed in Cytyc's filings with the Securities and Exchange Commission, including those under the heading "Risk Factors" in its 2005 Annual Report on Form 10-K and its most recent Quarterly Report on Form 10-Q filed with the Commission. Cytyc cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date they were made. Cytyc disclaims any obligation to publicly update or revise any such statements to reflect any change in its expectations or events, conditions, or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.