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Pigmented basal cell carcinoma in Hispanics
Pigmented basal cell carcinoma in Hispanics Carl Bigler, MD, a Jerry Feldman, MD, a Elisa Hall, MD, b and R. Steven Padilla, MD ~ Albuquerque, New Mexico
Background: Pigmented basal cell carcinoma (PBCC) may occasionally be misdiagnosed as melanoma. In the Hispanic population, PBCC is common. Objective: We attempted to determine the prevalence of PBCC in a Hispanic population. Methods: A randomized, blinded, retrospective study was designed to assess histologic sfides for the presence of microscopic pigment. Basal cell carcinoma (BCCs) from 30 patients with a Hispanic surname were compared histologically with BCCs from 30 patients with a northem European surname. In the prospective phase of the study, 15 Hispanic and 44 non-Hispanic patients with clinically suspected BCC or PBCC completed a questionnaire about their ethnic background and skin type to determine whether PBCC is more common in Hispanics. Results: Pigment was identified twice as frequently in BCCs from patients with a Hispanic surname than in BCCs from patients with a northern European stmaame. In the prospective clinical study, 66% of clinically diagnosed PBCCs were found in Hispanic patients, whereas only 11% of nonpigmented BCCs came from Hispanic patients (p < 0.01). Conclusion: In patients with a BCC, PBCCs are more common in Hispanics than non-Hispanics. This may reflect an increased incidence of PBCCs in the Hispanic population. (J AM ACAD DERMATOL1996;34:751-2.)
Pigmented basal cell carcinoma (PBCC) m a y have features suggestive of melanoma such as an irregular border, and dark or variable pigment (Fig. 1). Although basal cell carcinoma (BCC) and melanoma are about sevenfold less frequent in New Mexico's Hispani c population than in New Mexico's non-Hispanic population, BCC is still much more frequently diagnosed than melanoma, i, 2 PBCC has been reported to be more frequent in North American black and Hispanic populations.3, 4, 5 However, most of these studies are case reports of clinical findings, often lacking control groups, or are histologic studies that do offer clinical correlation. This two-phase study was designed to determine whether PBCC is more common in Hispanic patients. MATERIAL AND METHODS
Phase I was a blinded retrospective examination of histologic slides selected from BCCs diagnosed at the From the Department of Dermatology, University of New Mexico School of Medicine,a and the Department of Pathology, Albuquerque Veterans Affairs Medical Center.b Accepted for publication Sept. 7, 1995. Reprint requests: Carl Bigler, MI), Departanent of Dermatology, University of New Mexico, 2701 Frontier, NE, Albuquerque, NM 87131. 16/1/69090
Fig. 1. Pigmented BCC. 751
752
Journal of the American Academy of Dermatology May 1996
Bigler et aL
T a b l e I. Phase 1I prospective study of clinical pigment in BCCs and skin type Skin type
PBCC
BCC
I
1
7
II 11I IV V
0 4 8 2
20 13 5 0
Albuquerque Veterans Affairs Medical Center. Thirty consecutive cases of BCC in patients with Hispanic surnames and 30 consecutive cases of BCC in patients with northern European surnames were examined. All slides were randomized, relabeled, and independently examined by each investigator (C. B., J. F., E. H., and R. S. P.). Pigment was graded as 0 (no pigment), 1 (trace; pigment seen with the 20x objective), and 2 (positive; pigment seen with the 4x objective) by each investigator. Significant pigment was defined as a total score of 4 (i.e., an average of trace pigment seen by each investigator). In phase H of the study, patients with clinically suspected BCCs during a 6-month period (Feb. 22 to Aug. 22, 1994) were questioned about their ethnic backgrotmd and sun sensitivity. A patient was considered of Hispanic background if at least one of his grandparents was Hispanic. There were 15 Hispanic and 44 non-Hispanic patients with clinically suspected BCCs and PBCCs. Each patient's skin type was defmed as type I to VI by evaluating responses to questions about tanning and sunburn. 6 All clinically pigmented and nonpigmented BCCs were confirmed histopathologically. All patients were examined and questioned by one investigator (C. B.). RESULTS
Significant pigment was present in 53% of biopsy specimens of BCC in patients with a Hispanic surname as compared with 23% of BCC specimens in patients without a Hispanic surname (p < 0.06). Pigment was most often located superficially in the dermis within macrophages adjacent to tumor nodules. Trace amounts of pigment were identified in several clinically nonpigmented BCCs. In the prospective clinical study of Hispanic patients, 66% of BCCs were PBCCs. In our non-Hispanic patients only 11% of BCCs had clinically apparent pigment (p < 0.01). PBCCs were also more common in patients with darker skin (Table I). The PBCCs were found in non-Hispanic patients who had darker skin
types HI and IV (five patients). This is in contrast to nonpigmented BCCs that were most frequent in skin type 11. DISCUSSION
PBCC is more common in persons of Hispanic origin and m a y be as common as nonpigmented BCC in this group. This could be the result of their darker skin color or some genetic predisposition unrelated to skin color. Evidence suggests a relation between skin color and PBCCs. PBCC occurs more frequently in other ethnic groups with a darker skin color such as blacks) The non-Hispanic patients with P B C C in this study also had darker skin types. P B C C should be considered in the differential diagnosis of pigmented lesions in Hispanic patients. Helpful clues to the diagnosis of P B C C include a translucent, pearly quality that is not completely masked by pigmentation, a firm consistency, and occasionally an ulcerated surface. Because melanoma is in the differential diagnosis of PBCC, the treatment of clinically diagnosed PBCC by electrodessication and curettage should be postponed until the diagnosis is confirmed histologically. If the lesion is a melanoma, curettage before diagnosis may prevent accurate measurement of tumor depth. The treatment of P B C C is the same as for BCC. The tumor borders are often more distinct because of the pigment, and an infiltrative growth pattern is less likely in PBCC than in the usual BCC. 7 REFERENCES
1. Scotto J, Fears TR, Fraumeni JF. Incidence of nonmelanoma skin cancer in the United States.NIH publicationNo. 83-2433:56-9. Bethesda,Md: National Institutesof Health, 1983. 2. Pathak DR, Samet JM, Howard CA, et al. Malignant melanoma of the skin in New Mexico. Cancer 1982;50:1140-6. 3. Abreo F, Sanusi ID. Basal cell carcinoma in North American blacks. J AM ACADDERMATOL1991;25:1005-11. 4. Smith LM, Garrett HD, Hart MS. Pigmented basal cell epithelioma. Arch Dermatol 1960;81:95-102. 5. Kalter DC, Goldberg LH, Rosen T. Darkly pigmented lesions in dark-skinned patients. J Dermatol Surg Oncol 1984;10:876-81. 6. Pathak MA. Sunscreens: topical and systemic approaches for protection of human skin against harmful effects of solar radiation. J AM ACADDERMATOL1982;7:285312. 7. Maloney ME, Jones DB, Sexton FM. Pigmented basal cell carcinoma: investigationof 70 cases. J AM ACADDERMATOL 1992;27:74-8.
Background: Pigmented basal cell carcinoma (PBCC) may occasionally be misdiagnosed as melanoma. In the Hispanic population, PBCC is common. Objective: We attempted to determine the prevalence of PBCC in a Hispanic population. Methods: A randomized, blinded, retrospective study was designed to assess histologic sfides for the presence of microscopic pigment. Basal cell carcinoma (BCCs) from 30 patients with a Hispanic surname were compared histologically with BCCs from 30 patients with a northem European surname. In the prospective phase of the study, 15 Hispanic and 44 non-Hispanic patients with clinically suspected BCC or PBCC completed a questionnaire about their ethnic background and skin type to determine whether PBCC is more common in Hispanics. Results: Pigment was identified twice as frequently in BCCs from patients with a Hispanic surname than in BCCs from patients with a northern European stmaame. In the prospective clinical study, 66% of clinically diagnosed PBCCs were found in Hispanic patients, whereas only 11% of nonpigmented BCCs came from Hispanic patients (p < 0.01). Conclusion: In patients with a BCC, PBCCs are more common in Hispanics than non-Hispanics. This may reflect an increased incidence of PBCCs in the Hispanic population. (J AM ACAD DERMATOL1996;34:751-2.)
Pigmented basal cell carcinoma (PBCC) m a y have features suggestive of melanoma such as an irregular border, and dark or variable pigment (Fig. 1). Although basal cell carcinoma (BCC) and melanoma are about sevenfold less frequent in New Mexico's Hispani c population than in New Mexico's non-Hispanic population, BCC is still much more frequently diagnosed than melanoma, i, 2 PBCC has been reported to be more frequent in North American black and Hispanic populations.3, 4, 5 However, most of these studies are case reports of clinical findings, often lacking control groups, or are histologic studies that do offer clinical correlation. This two-phase study was designed to determine whether PBCC is more common in Hispanic patients. MATERIAL AND METHODS
Phase I was a blinded retrospective examination of histologic slides selected from BCCs diagnosed at the From the Department of Dermatology, University of New Mexico School of Medicine,a and the Department of Pathology, Albuquerque Veterans Affairs Medical Center.b Accepted for publication Sept. 7, 1995. Reprint requests: Carl Bigler, MI), Departanent of Dermatology, University of New Mexico, 2701 Frontier, NE, Albuquerque, NM 87131. 16/1/69090
Fig. 1. Pigmented BCC. 751
752
Journal of the American Academy of Dermatology May 1996
Bigler et aL
T a b l e I. Phase 1I prospective study of clinical pigment in BCCs and skin type Skin type
PBCC
BCC
I
1
7
II 11I IV V
0 4 8 2
20 13 5 0
Albuquerque Veterans Affairs Medical Center. Thirty consecutive cases of BCC in patients with Hispanic surnames and 30 consecutive cases of BCC in patients with northern European surnames were examined. All slides were randomized, relabeled, and independently examined by each investigator (C. B., J. F., E. H., and R. S. P.). Pigment was graded as 0 (no pigment), 1 (trace; pigment seen with the 20x objective), and 2 (positive; pigment seen with the 4x objective) by each investigator. Significant pigment was defined as a total score of 4 (i.e., an average of trace pigment seen by each investigator). In phase H of the study, patients with clinically suspected BCCs during a 6-month period (Feb. 22 to Aug. 22, 1994) were questioned about their ethnic backgrotmd and sun sensitivity. A patient was considered of Hispanic background if at least one of his grandparents was Hispanic. There were 15 Hispanic and 44 non-Hispanic patients with clinically suspected BCCs and PBCCs. Each patient's skin type was defmed as type I to VI by evaluating responses to questions about tanning and sunburn. 6 All clinically pigmented and nonpigmented BCCs were confirmed histopathologically. All patients were examined and questioned by one investigator (C. B.). RESULTS
Significant pigment was present in 53% of biopsy specimens of BCC in patients with a Hispanic surname as compared with 23% of BCC specimens in patients without a Hispanic surname (p < 0.06). Pigment was most often located superficially in the dermis within macrophages adjacent to tumor nodules. Trace amounts of pigment were identified in several clinically nonpigmented BCCs. In the prospective clinical study of Hispanic patients, 66% of BCCs were PBCCs. In our non-Hispanic patients only 11% of BCCs had clinically apparent pigment (p < 0.01). PBCCs were also more common in patients with darker skin (Table I). The PBCCs were found in non-Hispanic patients who had darker skin
types HI and IV (five patients). This is in contrast to nonpigmented BCCs that were most frequent in skin type 11. DISCUSSION
PBCC is more common in persons of Hispanic origin and m a y be as common as nonpigmented BCC in this group. This could be the result of their darker skin color or some genetic predisposition unrelated to skin color. Evidence suggests a relation between skin color and PBCCs. PBCC occurs more frequently in other ethnic groups with a darker skin color such as blacks) The non-Hispanic patients with P B C C in this study also had darker skin types. P B C C should be considered in the differential diagnosis of pigmented lesions in Hispanic patients. Helpful clues to the diagnosis of P B C C include a translucent, pearly quality that is not completely masked by pigmentation, a firm consistency, and occasionally an ulcerated surface. Because melanoma is in the differential diagnosis of PBCC, the treatment of clinically diagnosed PBCC by electrodessication and curettage should be postponed until the diagnosis is confirmed histologically. If the lesion is a melanoma, curettage before diagnosis may prevent accurate measurement of tumor depth. The treatment of P B C C is the same as for BCC. The tumor borders are often more distinct because of the pigment, and an infiltrative growth pattern is less likely in PBCC than in the usual BCC. 7 REFERENCES
1. Scotto J, Fears TR, Fraumeni JF. Incidence of nonmelanoma skin cancer in the United States.NIH publicationNo. 83-2433:56-9. Bethesda,Md: National Institutesof Health, 1983. 2. Pathak DR, Samet JM, Howard CA, et al. Malignant melanoma of the skin in New Mexico. Cancer 1982;50:1140-6. 3. Abreo F, Sanusi ID. Basal cell carcinoma in North American blacks. J AM ACADDERMATOL1991;25:1005-11. 4. Smith LM, Garrett HD, Hart MS. Pigmented basal cell epithelioma. Arch Dermatol 1960;81:95-102. 5. Kalter DC, Goldberg LH, Rosen T. Darkly pigmented lesions in dark-skinned patients. J Dermatol Surg Oncol 1984;10:876-81. 6. Pathak MA. Sunscreens: topical and systemic approaches for protection of human skin against harmful effects of solar radiation. J AM ACADDERMATOL1982;7:285312. 7. Maloney ME, Jones DB, Sexton FM. Pigmented basal cell carcinoma: investigationof 70 cases. J AM ACADDERMATOL 1992;27:74-8.