July 2017

Dentist Misjudges Patient's Tongue Lesion, Resulting in Missed Oral Cancer Diagnosis

Mario Catalano, DDS, MAGD


A necessary prerequisite to efficacious dental treatment is an accurate diagnosis. Misdiagnosis can result in failure to treat, undertreatment, or overtreatment. As this case illustrates, accurate diagnosis requires diligence in ordering appropriate testing or, at a minimum, thorough follow‐up to ensure that the patient's condition resolves on its own.

Case Discussion

A 46‐year‐old female was a patient of record at a dental practice in which Dr. N, a young dentist, was an associate. Dr. N's first contact with the patient occurred when she presented to the practice with a complaint of a "sore" that suddenly appeared on the left lateral aspect of her tongue. Dr. N's examination notes indicated that he believed the lesion was lichen planus. However, his notes did not indicate any differential diagnoses or state whether the patient had experienced any recent trauma or illness. If Dr. N was correct in diagnosing lichen planus, he could expect that the condition, although chronic, would not require treatment.

Approximately 2 weeks later, the patient presented to her family physician with complaints of coughing and gastrointestinal symptoms; however, no evidence suggests that the patient complained of any discomfort in her tongue. Further, the family physician did not note any irregularity in relation to the patient's tongue.

About 6 weeks after the patient visited her physician, she presented to the dental practice for a cleaning, which was done by a hygienist. Following the cleaning, Dr. N performed an oral examination. He did not note any abnormality of the patient's tongue. However, during subsequent investigation, it was learned that the hygienist had observed a 2–3 mm lesion on the left lateral aspect of the patient's tongue. Whether this lesion was brought to Dr. N's attention is not documented or known; obviously, though, no further evaluation of the lesion occurred.

Approximately 5 weeks later, the patient again presented to Dr. N for extraction of teeth 15 and 18. The removal of tooth 15 involved considerable difficulty, and the patient and Dr. N decided wait to remove tooth 18. Dr. N's notes regarding the removal of tooth 15 did not indicate any difficulty with the extraction, and they contained no reference to the previously discussed tongue lesion. For whatever reason, the extraction of tooth 15 was the last time the patient had any contact with Dr. N.

About 5 months after the extraction of tooth 15, the patient presented to her family physician with a complaint of a sore throat. The physician's notes stated that an examination of the palate, tongue, and tonsils did not indicate anything unusual. The patient had four additional encounters with her family physician for chest congestion issues over the winter, but the physician did not document any abnormal appearance associated with the patient's tongue.

Approximately 6 months after that, the patient presented to an emergency department with a complaint of left‐sided facial pain and blisters on her tongue. The emergency physician noted that tooth 18 (which had never been extracted) appeared to be abscessed. The patient was prescribed antibiotics and referred to an ENT practice. Two days later, an ENT surgeon noted a large red mass over the medial third of the patient's tongue, possibly caused by the problems associated with tooth 18. The ENT surgeon ordered a CT scan of the patient's neck to rule out a neoplasm and referred the patient to an oral and maxillofacial surgeon for treatment of tooth 18. The radiologic report indicated a 17 mm mass on the patient's tongue with nodal involvement. Ultimately, she was diagnosed with stage IV squamous cell carcinoma of the tongue.

The patient brought a dental malpractice lawsuit against Dr. N, alleging failure to timely diagnose cancer in her tongue. Despite numerous occasions in which Dr. N potentially had the opportunity to properly diagnose the patient, the jury returned a verdict in favor of the defense.



Risk Management Considerations

Theodore Passineau, JD, HRM, RPLU, CPHRM, ASHRM

The defense verdict in this case is particularly surprising given the fact that Dr. N appears to have mishandled this case on multiple occasions, resulting in a catastrophic outcome for the patient. Although time could be spent speculating about the outcome of the case, Dr. N might have avoided the courtroom altogether if he had implemented certain patient safety and risk management strategies.

The problems with this case began during the patient's first encounter with Dr. N, in which the patient complained about a "sudden sore" on her tongue. Dr. N rendered a presumptive diagnosis of lichen planus, which — although chronic — would require no further treatment. This diagnosis should not have been considered final for several reasons: (1) the lesion was not in the normal anatomical location, (2) the diagnosis was not supported by any historical evidence, and (3) no biopsy had been performed to confirm the diagnosis. The best practice in this situation would have been for Dr. N to consider lichen planus a presumptive diagnosis and follow the patient until it was clear that the diagnosis was correct.

The patient's record demonstrates numerous opportunities for Dr. N to reexamine and evaluate the lesion, but that never happened. At least two factors appear to have contributed to this failure. First, Dr. N's documentation generally appears to be inadequate; even if he took the time to review the patient's record prior to seeing her during subsequent visits, any concerns he might have had about the lesion likely would not be brought to his attention (because they were not adequately noted). In cases like this, in which follow‐up is needed to rule out more serious conditions, the doctor's concerns should be recorded in a "tickler system" of some sort, so that the practitioner is reminded to follow‐up with the patient.

Second, during legal discovery, it was determined that the hygienist had observed the lesion. However, whether the hygienist notified Dr. N about the presence of the lesion is not known. If the hygienist had reviewed the patient's record prior to the prophylaxis, she might have seen the reference to the lesion and realized that it had not resolved. However, regardless of whether she was aware of the lesion before observing it, she should have brought it to Dr. N's attention. Again, the exact situation that occurred is not clear, but it seems likely that the communication between Dr. N and the hygienist was inadequate.

The lack of documentation in this case combined with poor communication and failure to follow up ultimately deprived the patient of a timely diagnosis and, in all likelihood, a much better outcome. As is often the case, nonclinical factors combined to cause a suboptimal clinical outcome.


In dental practice, as in all aspects of life, so often "the devil is in the details." As this case illustrates, mundane (and even boring) tasks such as thorough documentation and good communication can be critical components of quality patient care. Disciplining oneself to do the little things well can contribute to satisfying and successful patient care experiences.


How can dentists use electronic documentation systems (i.e., an electronic health record system) to maximize patient safety?


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