APRIL 15, 2010 • WWW.INTERNALMEDICINENEWS.COM DERMATOLOGY 37 Partial Biopsies of Lesions Leave Room for Error

BY KERRI WACHTER sion that will have the worst representative histology,” Dr. Marghoob said. In one study, 40% of excised isdiagnosis of melanoma is a major cause of melanomas had worse pathology, compared with ini- litigation against both physicians and der- tial punch biopsy, and 20% of melanomas revealed in- Mmatopathologists. ARGHOOB vasion that was not seen in initial punch biopsy (Arch. Of all claims between 1985 and 2001, 14% involved A. M Dermatol. 1996;132:1297-302). misdiagnosis of melanoma, Dr. Ashfaq A. Marghoob The ideal biopsy is excisional with a 2- to 3-mm mar- reported at the annual Hawaii Dermatology Seminar SHFAQ gin, is oriented along the lines of lymphatic drainage, . A sponsored by Skin Disease Education Foundation. R and is step sectioned. This limits sampling error, re- Furthermore, the majority of claims involving the D moves dysplastic nevus completely (preventing recur- misdiagnosis of melanoma were because of a false-neg- rence), and better predicts the Breslow depth if the le- ative diagnosis, which may translate to a reduced sion proves to be a melanoma, Dr. Marghoob said. chance of survival for some patients, said Dr. Misdiagnosis of a melanoma as dysplastic or spitz MAGES COURTESY Marghoob, who is a dermatologist at Memorial Sloan- I nevus. When a partial biopsy reveals dysplastic or Kettering Cancer Center in New York. Partial biopsies of this melanoma yielded results spitz nevus, it is important to completely excise the le- Two important strategies can help minimize missing ranging from Clark’s nevus to invasive melanoma. sion. Malignant melanoma can sometimes masquerade melanoma, he said. as a spitz nevus, and focus of malignant melanoma may First, remain vigilant and remember that many melanoma with an unknown primary or recurrence of have been missed on the biopsy. Many dermatologists melanomas lack the classic ABCD features. “Ques- melanoma (Am. J. Surg. Pathol. 2003;27:1278-83). are of the opinion that spitz nevi should be complete- tioning yourself and your pathologist regarding the di- Dr. Marghoob discussed these common scenarios: ly excised, he said. agnosis will help towards identifying many of these Misdiagnosis of nodular melanoma as nevus by a Unrecognized desmoplastic malignant melanoma. melanomas. In other words, remain skeptical of lesions clinician or pathologist. Many nodular melanomas Desmoplastic melanoma can be banal in appearance, lacking clinical-dermoscopy correlation or lesions lack- lack helpful diagnostic features, such as those in the with 70% appearing amelanotic, he said. These lesions ing dermoscopy-histopathology correlation. ABCD criteria for malignant melanoma, which can lead may only present as firmness in the subcutaneous tis- “Second, engage patients in their own care by hav- to a misdiagnosis. However, the ABCDE criteria that sue. For banal-appearing firm lesions on chronically ing them share the responsibility of detecting early take lesion evolution into account may be of some help, sun-damaged skin, suspicion should be raised if the le- melanoma by encouraging them to examine their own Dr. Marghoob noted. sions are symptomatic, growing, associated with a skin on a regular basis,” he said. To track lesion evolution, ask patients about the his- lentigo maligna, or reveal irregular vessels with der- Some melanomas may not manifest concerning fea- tory of changes and symptoms. Total body photography moscopy, Dr. Marghoob said. tures, and can mimic benign lesions. To ensure that a may help on rare occasions to detect new lesions, some Metastatic melanoma with unknown primary or malignant melanoma will eventually be found, both pe- of which may be subtle. Dermoscopy results may per- recurrence of melanoma. Whenever possible, do not riodic total body examinations by a physician and reg- suade the clinician to obtain a biopsy of a clinically ba- remove seemingly benign lesions and discard them, he ular patient self-examinations are key. nal–appearing lesion that is in fact a nodular melanoma. said. Also, be careful and selective about the use of liq- Although it is widely accepted that early detection Partial biopsy issues. If a biopsy is performed of a uid nitrogen or a laser on lesions that have not been con- means better prognosis, modest delays of up to 6 lesion that clinically looks like melanoma and the firmed to be benign through biopsy. months have not been shown to affect ultimate out- pathology diagnosis is nevus, it is imperative that the He noted that cases of assumed benign lesions that comes. However, there is one exception: Nodular clinician and pathologist reconcile the difference. In cas- recur after ablation (via liquid nitrogen, curettage, or melanoma can grow rapidly, and even small delays in es where there is discordance, consider asking for step- laser) may ultimately prove to be melanoma on diagnosis can have serious consequences. sectioning, special stains, or—in very rare instances— histopathology. Furthermore, in the unlikely event The most common scenarios in melanoma litigation fluorescence in situ hybridization to look for signature that a patient develops metastatic melanoma with an cases include nodular melanoma being misdiagnosed chromosomal aberrations. Excisional biopsy is the pre- unknown primary, it may be presumed that one of the by a clinician or pathologist, a partial biopsy not cap- ferred method for melanocytic lesions, when possible, ablated lesions was the primary. ■ turing the most diagnostically relevant part of the le- because partial biopsy may sample nondiagnostic areas sion, malignant melanoma being misdiagnosed as a dys- or miss the prognostically worse portion of the lesion. Disclosures: Dr. Marghoob disclosed having no conflicts of plastic or spitz nevus, unrecognized desmoplastic “Partial biopsy assumes that a clinician can consis- interest. SDEF and this news organization are owned by malignant melanoma, and metastatic malignant tently predict the portion of a suspicious pigmented le- Elsevier. About 5% of Melanoma Patients Have Subsequent Melanoma

BY DOUG BRUNK vision of dermatology at Scripps Clinic al statistics for all primary melanomas. atypical melanocytic hyperplasia or an- Rancho Bernardo in San Diego. “But the second primary melanoma other worrisome diagnosis.” S AN D IEGO — The chances of a pa- He went on to note that the risk of tends to be thinner than the first one, The other possibility is that incidence tient’s developing multiple primary multiple primary melanomas is twofold which makes sense,” Dr. Burrows com- of melanoma is rising. “We know that melanomas over a lifetime is a real phe- higher among men, and that the major- mented. “After the first primary we are making the diagnosis of primary nomenon, with an incidence ranging ity of subsequent primary melanomas melanoma we raise our index of suspi- melanomas at a younger age than we did from 2% to 8% among patients who cion on lesions that are irregular. In ad- 20 years ago,” Dr. Burrows said. have had a first melanoma, or an average dition, the patient has a significant level In the Scripps series, 75% of patients of about 5%. ‘I have about four of worry.” had two primary melanomas, 15% had “That’s significantly higher than if people I follow Recognized risk factors for multiple three, and the remainder had four or we apply the risk of melanoma to all who have had melanomas include presence of atypical/ more. The average age at initial prima- fair-skinned people in the country,” five or six dysplastic nevi, family history, and early ry melanoma diagnosis was 64 among Dr. William M. Burrows observed at a primary age of onset. men and 56 among women. melanoma update sponsored by the melanomas.’ According to a retrospective review of Nearly half of the patients (49%) de- Scripps Clinic. 1,258 melanoma patients treated at the veloped subsequent melanomas less than Of patients who develop additional DR. BURROWS Scripps Clinic between 1990 and 2000, 3 years after their initial primary mela- melanomas, about 80% develop one in 149 (12%) developed multiple primary le- noma diagnoses. addition to the original, 15% develop (70%) occur on a different anatomical sions, which is more than double the na- When managing patients with multi- two, and the remainder develop three or site, while 30% occur on the same site. tional incidence. “This could be due to ple melanomas, a full skin exam during more. “They have the same distribution as one of two things,” Dr. Burrows said. initial work-up and follow-up intervals is “In my practice I have about four peo- melanomas in general,” he said. “One is the criteria that are used in mak- essential, he said. “Follow-up should be ple I follow who have had five or six pri- The majority of subsequent primary ing the diagnosis of melanoma in situ. I lifelong.” ■ mary melanomas,” said Dr. Burrows, melanomas occurs after 2 months, while wonder if we [at Scripps] diagnose who has practiced dermatology for near- 30% occur within 2 months or less. melanoma in situ more often, as op- Disclosures: Dr. Burrows said he had no ly 40 years and is currently with the di- Depth of invasion is similar to nation- posed to others who might sign it out as financial conflicts.