Count 1 of the declaration in an action of *137tort alleged that the defendant, a surgeon, failed to remove the plaintiff’s appendix completely during an operation, on May 1,1949, was doubtful whether he had done so, and negligently failed to inform the plaintiff of his doubts, with the consequence that the plaintiff later “provided an inaccurate . . . medical history to . . . [a] physician whom he subsequently consulted regarding . . . abdominal pains, and accordingly was unnecessarily subjected to a series of . . . operations commencing . . . about January 23, 1957 . . . to his damage. ’ ’ Count 2 recited essentially the same averments with the addition of allegations that the surgeon ‘1 represented . . . that the operation had been a complete success, the appendix completely removed and the danger of further appendicitis attacks removed; [and] that the plaintiff relied on . . . [the surgeon’s] failure to . . . inform him as to his doubt,” to the plaintiff’s damage.
The statute of limitations was pleaded in the answer. See G. L. c. 260, § 4 (as amended through St. 1955, c. 235, § 1; see St. 1960, c. 271). The writ was dated December 9, 1958.
At the close of the plaintiff’s evidence, the surgeon rested without introducing evidence. The case is here on the plaintiff’s exception to the direction of a verdict for the surgeon on each count. The evidence is stated in its aspect most favorable to the plaintiff.
The operation on May 1, 1949, lasted about two hours. The surgeon in notes described the operation as follows: “Bight Bectus incision. No free fluid in abdomen. Small intestine distended. Cecum tied down. Appendix finally found Betrocecal and at the bottom of a mushy area. The appendix was covered with adhesions, was very small and was tied down. . . . [T]he tissues were very friable and the clamps tore off and there was brisk bleeding for a few minutes. Vessels reclamped and tied. Appendix removed to what appeared to be the base, but there were such dense adhesions that it was impossible to be certain and the raw oozing area at the bottom of the space was considerable. A piece of oxycel gauze was placed at the bottom of wound *138over the ooze. It was dry on closing. Abdomen closed in layers with great difficulty because of [s]pasm and [tightness which was finally overcome with [e]ther and curare. Patient left Operating] R[oom] in good condition” (emphasis as it appears in record). Following the operation, the surgeon informed the plaintiff that the operation had been long because “it had taken a long time to find the appendix.” The surgeon “made no further report to . . . [the plaintiff] then or later about the operation or the appendix.”
The plaintiff was discharged from the hospital approximately ten days after the operation. He “had no abdominal operations or . . . pain . . . until on or about January 14, 1957,” nearly eight years later. As a result of symptoms then developing, he consulted Dr. Meyer, a general practitioner in Schenectady, where the plaintiff then resided. Dr. Meyer testified that the plaintiff’s symptoms “were consistent with several abdominal disorders, but were particularly suggestive of appendicitis.” He, however, noted the “rectus scar, and . . . [the plaintiff] reported . . . that his appendix had been removed ... in 1949.” As a consequence Dr. Meyer omitted certain 1 ‘ standard medical tests in cases of suspected appendicitis, and diagnosed . . . [the] illness as gastro-enteritis or ‘intestinal grippe.’ ”
The pain continued during the following week increasing to acute on January 23. Dr. Breault, a surgeon, was consulted. He “operated on . . . [the plaintiff] locating a large abscess ... of infectious pus, together with considerable local peritonitis, caused by a ruptured appendix. He drained the abscess, but was unable to remove the ruptured vestige of the appendix because of the wide spread infection.” He also stated “that the abscess would not have formed, and the operation to drain it would not have been necessary, if the appendicitis condition had been discovered and the diseased appendix removed before it had ruptured.”
Further operations occurred. These were “to relieve *139post-operative . . . [difficulties] caused by the prior infectious condition discovered during the January 23rd operation.” In Dr. Breault’s opinion, they would not have been necessary had the January, 1957, condition been discovered before the appendix ruptured. In one of the later operations, “an elective appendectomy ... to eliminate the danger of further appendicitis attacks,” the “vestige of the appendix . . . slightly under . . . [one] inch long, was removed.” The plaintiff “alleges no breach of duty with respect to the performance of the . . . appendectomy of May, 1949,” and places “no reliance on an allegation of a concealment of any such breach of duty.”
1. Count 1 essentially alleges negligence on the part of the surgeon in failing to inform the plaintiff of the surgeon’s doubts at the time of the 1949 operation. It was, of course, the defendant’s duty to exercise the degree of care and skill which members of the medical profession in the community commonly possess and exercise in like circumstances. See Semerjian v. Stetson, 284 Mass. 510, 512-513, 514-515; Berardi v. Menicks, 340 Mass. 396, 400-402.
Dr. Breault testified that “it is standard appendectomy procedure to remove the appendix completely, leaving no stump or vestige at the cecum.” This testimony, however, falls short of being evidence of the knowledge and understanding in 1949 of members of the medical profession in the community about the extent of risk to the patient involved where a small vestige of appendix was not removed.
“It is only in exceptional cases that a jury instructed by common knowledge and experience may without the aid of expert medical opinion determine whether the conduct of a physician toward a patient is violative of the special duty which the law imposes as a consequence of this particular relationship.” See Bouffard v. Canby, 292 Mass. 305, 309; Tallon v. Spellman, 302 Mass. 179,183; Kiley v. Dervin, 314 Mass. 478, 483-484; Riggs v. Christie, 342 Mass. 402, 405-407, and cases cited. See also Vigneault v. Dr. Hewson Dental Co. 300 Mass. 223, 225-227. The exceptional cases seem to be those “where the negligence and harmful results are sufficiently obvious as to lie within common knowledge.” *140Cyr. v. Giesen, 150 Maine, 248, 252. See Toy v. Mackintosh, 222 Mass. 430, 431-432; Marangian v. Apelian, 286 Mass. 429, 436-437; Malone v. Bianchi, 318 Mass. 179, 181 — 182. See also Beane v. Perley, 99 N. H. 309, 310-311; Wigmore, Evidence (3d ed.) § 2090; Annotation, 141 A. L. R. 5, 6,12. Cf. Traverse v. Wing, 256 Mass. 320, 321-323.
The plaintiff relies to some extent upon the recent case of Berardi v. Menicks, 340 Mass. 396, 399-401, where this court considered the conduct of a dentist in connection with wisdom teeth extractions. The dentist (p. 400) “admitted that normal procedure would require the extraction of the whole tooth.” There was evidence that “following the operation, while still being treated by the . . . [dentist], the plaintiff had serious trouble with her jaw.” The jury could have found (p. 401) that the dentist had “knowledge . . . that roots still remained in the plaintiff’s jaw [and] took no steps to remove them,” and also that the dentist “did not inform the plaintiff of the unextracted roots.” There was medical evidence of causal connection (pp. 401-402) between the conduct of the dentist and injuries to the plaintiff. The dentist’s own testimony was that “he endeavored without success to communicate with . . . [the plaintiff] several times for the purpose of permitting him to complete his dental care by removing the roots.” The aggregate professional testimony mentioned above adequately indicated the existence of a significant risk in leaving the roots unremoved.
We do not have before us a case where there is certainty of a foreign object or a dangerous physical organ left in a patient during an operation and it is obvious that a substantial and definable risk has been created. Cf. Ernen v. Crofwell, 272 Mass. 172, 175; Dietze v. King, 184 F. Supp. 944, 948-949 (E. D. Va.); Morrison v. Acton, 68 Ariz. 27, 35; Slimak v. Foster, 106 Conn. 366,367,371 (but see Frogge v. Shugrue, 126 Conn. 608, 611); Smith v. Zeagler, 116 Fla. 628, 632; Taylor v. Milton, 353 Mich. 421, 425-426; Benson v. Dean, 232 N. Y. 52, 56 (needle fragment); Hinkle v. Hargens, 76 S. D. 520. Cf. also Reid v. United States, 224 F. 2d 102, 103-104 (5th Cir.), S. G. after trial on the merits, sub *141nom. United States v. Reid, 251 F. 2d 691, 692-693 (5th Cir.); Shutan v. Bloomenthal, 371 Ill. 244, 254; Wambold v. Brock, 236 Iowa, 758, 761, 763. On the contrary, without expert testimony laymen, including the jury, the trial judge, and ourselves, could not be, and are not, in a position to determine what the risk and the requirements of professional conduct in the circumstances were in the neighborhood of Boston in 1949. Of their own knowledge laymen could not appraise whether, even if a vestige did remain after the 1949 operation, it created a definable risk then regarded as sufficiently substantial by practitioners in the locality so that good practice called for discussion of the uncertainty with the patient. This was a medical matter about which laymen should not guess. It was incumbent on the plaintiff to show by expert medical testimony that an incomplete removal of the appendix in the circumstances created a definable and substantial medical risk and that this was known, or should have been known, to the surgeon. Only upon such a showing would there be any basis for finding a duty of discussion with and disclosure to the patient. The situation called for expert guidance. See Ramsland v. Shaw, 341 Mass. 56, 59-62. Cf. Stewart v. Worcester Gas Light Co. 341 Mass. 425, 43A-435. This does not seem to us a case where “even the merest tyro would know [the surgeon’s conduct] was improper” (see Ballance v. Dunnington, 241 Mich. 383, 387) but one where professional knowledge and judgment are involved. A majority of the court think that this situation stands upon a different footing from the matters which, in certain eases already cited, have been treated as ‘ sufficiently obvious as to lie within common knowledge.” The absence of expert evidence of the existence and extent of any definable risk renders irrelevant any discussion of a special professional duty (see Dietze v. King, 184 F. Supp. 944, 948-949 [E. D. Va.]; Di Filippo v. Preston, 3 Storey [Del.] 539, 549-550) or general duty to warn of known and substantial dangers. Cf. Cutter v. Hamlen, 147 Mass. 471, 475; Guinan v. Famous Players-Lasky Corp. 267 Mass. 501, 511; Thorneal v. Cape *142Pond Ice Co. 321 Mass. 528, 532; Tomao v. A. P. De Sanno & Son, Inc. 209 F. 2d 544, 546 (3d Cir.), purporting to apply Massachusetts law.
2. Count 2 sounds in deceit. There was evidence, in addition to what has already been summarized, that, following the operation, the plaintiff asked the surgeon why the operation had taken so long and that the surgeon (who “made no further report to . . . [the plaintiff] then or later about the operation or the appendix”) replied “that it had taken a long time to find the appendix. ’ ’ There is no evidence of any affirmative misrepresentation, cf. Allison v. Blewett, 348 S. W. 2d 182 (Tex. Civ, App.), or any statement of fact, without disclosure of other known facts which might affect that statement. Cf. Burns v. Dockray, 156 Mass. 135, 137-138. Cf. also Yorke v. Taylor, 332 Mass. 368, 371. Any contention that there was deceit must rest upon the surgeon’s failure to comply with some duty to disclose his doubts. See Windram Mfg. Co. v. Boston Blacking Co. 239 Mass. 123,126; Stetson v. French, 321 Mass. 195, 198-199. We think that whether there was a duty to disclose depends upon whether there was, in the circumstances, conduct which would have been noncompliance with the special duty (see Vartanian v. Berman, 311 Mass. 249, 253) created by the doctor-patient relationship. As has been stated in the discussion of count 1 above, no expert medical evidence has established the existence and extent of any definable risk, which would be the foundation of whatever obligation the surgeon had in the circumstances in the community in 1949, so that it could be ascertained whether the surgeon’s conduct was inconsistent with that duty.
3. A verdict for the surgeon was properly directed on each count. We do not reach questions based upon the statute of limitations.
Exceptions overruled.