<Page> EXHIBIT 3.109 CHARTER OF PCA OF DENVER, INC. ARTICLE ONE NAME The name of the corporation is PCA of Denver, Inc. ARTICLE TWO PROFIT CORPORATION The corporation is organized for profit. ARTICLE THREE REGISTERED OFFICE AND AGENT The initial registered office of the corporation is located at 20 Burton Hills Boulevard, Nashville, Davidson County, Tennessee 37215. The initial registered agent of the corporation at its registered office is Brian C. Carr. ARTICLE FOUR PRINCIPAL OFFICE The mailing address of the initial principal office of the corporation is 20 Burton Hills Boulevard, Suite 220, Nashville, Tennessee 37215. ARTICLE FIVE AUTHORIZED SHARES The total number of shares of all classes of capital stock which the Corporation shall have the authority to issue is one thousand (1,000) shares of common stock, $.01 par value per share, with unlimited voting rights and rights to receive the net assets of the corporation upon dissolution. <Page> ARTICLE SIX INITIAL BOARD OF DIRECTORS The initial Board of Directors shall consist of one member whose name and address are as follows: Brian C. Carr Pathology Consultants of America, Inc. 20 Burton Hills Boulevard Suite 220 Nashville, Tennessee 37215 ARTICLE SEVEN LIMITATION OF DIRECTOR LIABILITY A director of the corporation shall not be liable to the corporation or to its shareholders for monetary damages for breach of fiduciary duty as a director, except for (a) any breach of the director's duty of loyalty to the corporation or its shareholders; (b) acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law; or (c) under Section 48-18-304 of the Tennessee Business Corporation Act (the "Act") Any repeal or modification of the provisions of this Article Seven by the shareholders of the corporation shall be prospective only, and shall not adversely affect any limitation on the personal liability of a director of the corporation with respect to any act or omission occurring prior to the effective date of such rcpeal or modification. If the Act is hereafter amended to authorize the further elimination or limitation of the liability of directors, then the liability of a director of the corporation, in addition to the limitation on liability provided herein, shall be limited to the fullest extent permitted by such amended Act. In the event that any of the provisions of this Article Seven (including any provision within a single sentence) is held by a court of competent jurisdiction to be invalid, void or otherwise unenforceable, the remaining provisions are sever able and shall remain enforceable to the fullest extent permitted by law. -2- <Page> ARTICLE EIGHT INCORPORATOR The name and address of the incorporator are as follows: Peter C. November Alston & Bird LLP 1201 West Peachtree Street Atlanta, Georgia 30309-3424 IN WITNESS WHEREOF, the undersigned executes this Charter this 11th day of December, 1997. /s/ Peter C. November ---------------------------------- Peter C. November Incorporator -3-