Failure to diagnose melanoma

By the TMLT Risk Management Department

This closed claim study is based on an actual malpractice claim from Texas Medical Liability Trust. This case illustrates how action or inaction on the part of the physicians led to allegations of professional liability, and how risk management techniques may have either prevented the outcome or increased the physicians’ defensibility. This study has been modified to protect the privacy of the physicians and the patient.

Presentation
A 48-year-old man came to his family physician requesting a refill for his allergy medication and an evaluation of a skin lesion on his back. The lesion had only recently appeared. The patient’s history was significant for Hodgkin’s disease that had remained in remission since treatment.

The physician’s documentation did not mention an exam or treatment of the lesion, but the patient was scheduled for a follow up visit.

Physician action
The patient returned to the practice 11 days later. During this visit, the family physician documented a 2 cm seborrheic keratosis on his back and performed cryotherapy on the lesion.

Nearly one month later, the patient sought treatment for sinus symptoms and requested a re-check of his “mole.” The patient encounter note did not include any reference to the lesion; however, billing records indicated that a repeat cryotherapy treatment was performed at this visit. The patient was treated over the next year at five visits, primarily for upper respiratory infections.

A year after the initial diagnosis of the patient’s lesion, he returned to the practice with a chief complaint of hematuria.

A urology work up revealed two large lesions in the bladder diagnosed as invasive malignant melanoma. Since a primary melanoma in the bladder is extremely rare, the oncologist ordered testing to determine the source of the patient’s primary melanoma. CT and PET scans failed to show any primary melanoma tumor.

A pathologist/dermatologist reviewed the biopsy results of the lesion on the patient’s back previously treated by the family physician. He concluded that although a diagnosis of benign keratosis was favored, the possibility of a regressive melanocytic neoplasm could not be excluded.

The oncologist treated the patient for primary bladder melanoma and recommended surgery. A bladder resection with excision of the tumors was performed. Pathology slides revealed deep bladder muscle invasion with melanoma.

Two weeks later, the patient underwent an MRI that showed multiple brain lesions consistent with the melanoma diagnosis. Treatment was only marginally effective and the patient died.

Allegations
A lawsuit was filed against the family physician. The allegations included:

• failure to properly evaluate, diagnose, and treat the lesion;
• failure to refer the patient to a dermatologist for evaluation of the lesion;
• failure to perform a biopsy or obtain a pathological analysis of the lesion; and
• failure to timely provide or order proper and immediate care and treatment.

Legal implications
A diagnosis of seborrheic keratosis was made at the visit in which the first cryotherapy was performed. The physical examination included the length of the lesion (2 cm). It was determined that this diagnosis was well within the scope of practice for a family physician.

The defendant reasoned that since the lesion was a classic seborrheic keratosis, it was not necessary to document all the reasons that it was not a melanoma. The issue of whether the original lesion was a melanoma and thus the original site of the malignancy proved to be a battle between the expert witnesses.

The plaintiffs’ experts reasoned that since primary malignant melanoma of the bladder is extremely rare — with only five to 10 documented cases in medical history — the probabilities strongly favored the conclusion that the urinary cancer represented a metastasis.

The defense experts argued that if the bladder tumors metastasized from the skin lesion, the work-up by the oncologist would have shown positive results from the PET and CT scans and two resections of skin lesions. All results from the comprehensive testing to determine the source of the melanoma were negative, including negative findings for axilla or groin lymph node involvement. It was also stated that metastatic melanoma from an unknown site occurs in 1 to 15 percent of cases.

A dermatopathologist involved in the subsequent work-up — who examined tissue later removed from the site of the treated lesion — concluded that he could not definitively state what type of lesion had previously been present and treated.

Disposition
Due to the weaknesses in the medical record documentation, the testimony of the pathologist, and the fact that the primary site of the melanoma could not be identified with certainty, the case was settled on behalf of the family physician.

Risk management considerations
The absence of documentation about the lesion during the visit when the second cryotherapy treatment was performed created a weakness for the defense. All experts agreed that if cryotherapy is performed on any lesion, it should be documented.

Upon questioning, the family physician could not recall the office visits or the reason he treated the patient’s lesion. When documentation in the medical record is absent or brief, the physician’s credibility and accuracy may be questioned.

The Texas Administrative Code Section 165.1 defines the Texas Medical Board rules for medical record keeping. The documentation requirements for each patient encounter in maintaining an “adequate” medical record includes the reason for the encounter with relevant history, physical examination findings, an assessment, clinical impression or diagnosis, and plan of care. 1

1. Texas Medical Board Rules. Texas Administrative Code Title 22, Part 9, Chapter 165, Section 165.1.

This closed claim study is published as an information and educational service. The information and opinions in this study should not be used or referred to as primary legal sources or construed as establishing medical standards of care for the purposes of litigation, including expert testimony. The standard of care is dependent upon the particular facts and circumstances of each individual case and no generalizations can be made that would apply to all cases. The information presented should be used as a resource, selected and adapted with the advice of your attorney. It is distributed with the understanding that neither Texas Medical Liability Trust nor its affiliates are engaged in rendering legal services.