Pediatric Melanoma Research Continues

Melanocytic nevi – spitz, congenital, and acquired – can pose diagnostic challenges for the pediatric dermatologist.

Dr. Jonathan A. Dyer offered a review of the latest literature on these pediatric melanomas at a seminar on women's and pediatric dermatology sponsored by Skin Disease Education Foundation.

Atypical Spitzoid Melanocytic Tumors (ASMT)

Data suggest that a positive sentinel lymph node biopsy (SLNB) in ASMT does not necessarily mean poor prognosis, according to Dr. Dyer, who is an assistant professor of clinical dermatology at the University of Missouri in Columbia.

Positive SLNB is not uncommon in ASMT, occurring in 28%-50% of cases. Nodal lesion morphology appears to be what matters – typical-appearing subcapsular cells versus ugly cells that replace a significant portion of the node (Am. J. Surg. Pathol. 2009;33:1386-95).

In a series of six published studies with more than 100 patients, no patient with ASMT and positive SLNB died of disease, he reported. However, follow-up was limited in many reports (median 10 months). Most malignant melanomas recur within 36 months.

In the Multicenter Selective Lymphadenectomy Trial (MSLT), the 5-year survival rate for patients younger than 19 years with malignant melanoma with a positive SLN was 68%, compared with 59% for adults.

Congenital Melanocytic Nevi (CMN)

A 19-year prospective study at Great Ormond Street Hospital in London provided a plethora of information on CMN (Br. J. Dermatol. 2009;160:143-50). The study included 349 families with CMN and 79 control families. Poor maternal health (threatened miscarriage, maternal hypertension, or severe nausea/vomiting) was associated with an increased incidence of CMN.

The researchers also found a possible positive association between maternal smoking and projected adult size and overall CMN incidence. CMN was more likely in females, while maternal freckling was independently associated with smaller projected adult size. A quarter of those with CMN had a second-degree relative with CMN, noted Dr. Dyer.

Furthermore, it is estimated that 5%-30% of patients with large CMN have asymptomatic neurocutaneous melanosis (NCM). NCM symptoms – increased intracranial pressure or seizures – typically occur in the first 2 years of life, he reported. It is possible for patients to convert from asymptomatic NCM to symptomatic but it is unclear how common it is (J. Clin. Oncol. 2009;27:e136).

Occasionally NCM symptoms are temporary or controllable; however, prognosis of symptomatic NCM is guarded. MRI is sensitive for NCM in the first 4-6 months but small deposits can be missed.

In terms of risk, satellites appear to be a major risk factor for NCM in patients with CMN. If there are no satellites, the risk of NCM is very low, summarized Dr. Dyer. In addition, CMN size appears to matter more than location. Based on several studies, the risk of NCM tends to be about 20%.

It has been suggested that up to two-thirds of pediatric patients with NCM go on to develop leptomeningeal tumors. Some patients may develop symptomatic NCM as a result, reported Dr. Dyer. An estimated 50%-90% of these patients die within 3 years of symptom onset. It is also estimated that 50% develop malignant melanoma of the central nervous system (Clin. Dermatol. 2009;27:529-36) .

Many CMN improve with time, he noted. In the Great Ormond Street study, for example, the majority of untreated lesions lightened during the follow-up period (Br. J. Dermatol. 2009;160:387-92). Surgery and the presence of satellites at birth were independently associated with darkening.

Satisfaction with surgery was high for patients with CMN of less than 20 cm and for those with facial lesions. However, satisfaction was reduced with increasing projected adult size. Girls were more likely to have surgery.

Treatment seemed to increase the darkening of remaining or later-developing nevi, independent of type, timing, or nevus. Tissue expansion appeared to be associated with increased satellite development, noted Dr. Dyer. Projected adult size was associated with satellite number but not treatment type.

Childhood Melanoma

Melanoma accounts for 1%-3% of childhood malignancies. The incidence increased by 2.9% per year from 1973 to 2001 (Clin. Dermatol. 2009;27:529-36). Melanoma is seven times more common in the second decade than in the first, said Dr. Dyer. It is estimated that teens aged 15-19 years account for 73%-79% of cases.

Interestingly, there is a slight male predominance in young children that changes to a slight female predominance in older groups. Adolescent white girls with a history of ultraviolet exposure have the greatest melanoma risk, particularly on the trunk and lower extremities, he pointed out.

Approximately 30% of childhood melanomas arise with giant CMN. Lifetime risk appears to be bimodal, with the first peak in the first decade of life (usually in the first 5 years). It is estimated that 50%-70% arise before puberty. Head and neck melanomas are more common at age 1-4 years, while melanomas on the trunk are more common with increasing age. Early-life melanomas tend to be dermal with poorer outcomes. The second peak occurs in adulthood, reported Dr. Dyer.

Approximately 20% of childhood melanomas occur with other melanocytic lesions. Malignant melanomas from small CMN typically occur after puberty. These are more similar to adult malignant melanomas.

Childhood melanomas are associated with an increased incidence of amelanotic and nodular lesions. Risk factors include the following: intermittent intense sun exposure, tendency to sunburn, tendency to freckle, fair skin, blue/green eyes, blonde/red hair, xeroderma pigmentosum, giant CMN, dysplastic nevus syndrome, atypical nevi, a family history of malignant melanoma, and immunosuppression.

The risk of transformation for CMN is associated with size. Small to medium CMN (less than 20 cm) have a 1%-5% risk of transformation, while large/giant CMN (greater than 20 cm) have at least a 5%-10% risk; however, the risk may be as great as 20%.

Some studies suggest that 30%-75% of pediatric malignant melanoma originated in giant CMN, and one-third are fatal, reported Dr. Dyer. Excision does not completely eliminate the risk. In one study, 8% of patients developed extracutaneous malignant melanoma after CMN excision.

He noted that the risk of childhood melanoma is associated with immunodeficiency. The risk is six times greater if immunodeficiency is genetic in origin; the risk is four times greater if immunodeficiency is acquired.

The indications for sentinel lymph node biopsy in children are the same as in adults, he noted. Children have a higher incidence positive sentinel lymph node. However, this does not predict likelihood of recurrence or prognosis in children.

Surgical excision should use the same margins as in adults whenever possible. Thickness, ulceration, and stage at diagnosis are all prognostic factors.

Disclosures: Dr. Dyer reported having no conflicts of interest. SDEF and this news organization are owned by Elsevier.

Melanocytic nevi – spitz, congenital, and acquired – can pose diagnostic challenges for the pediatric dermatologist.

Dr. Jonathan A. Dyer offered a review of the latest literature on these pediatric melanomas at a seminar on women's and pediatric dermatology sponsored by Skin Disease Education Foundation.

Atypical Spitzoid Melanocytic Tumors (ASMT)

Data suggest that a positive sentinel lymph node biopsy (SLNB) in ASMT does not necessarily mean poor prognosis, according to Dr. Dyer, who is an assistant professor of clinical dermatology at the University of Missouri in Columbia.

Positive SLNB is not uncommon in ASMT, occurring in 28%-50% of cases. Nodal lesion morphology appears to be what matters – typical-appearing subcapsular cells versus ugly cells that replace a significant portion of the node (Am. J. Surg. Pathol. 2009;33:1386-95).

In a series of six published studies with more than 100 patients, no patient with ASMT and positive SLNB died of disease, he reported. However, follow-up was limited in many reports (median 10 months). Most malignant melanomas recur within 36 months.

In the Multicenter Selective Lymphadenectomy Trial (MSLT), the 5-year survival rate for patients younger than 19 years with malignant melanoma with a positive SLN was 68%, compared with 59% for adults.

Congenital Melanocytic Nevi (CMN)

A 19-year prospective study at Great Ormond Street Hospital in London provided a plethora of information on CMN (Br. J. Dermatol. 2009;160:143-50). The study included 349 families with CMN and 79 control families. Poor maternal health (threatened miscarriage, maternal hypertension, or severe nausea/vomiting) was associated with an increased incidence of CMN.

The researchers also found a possible positive association between maternal smoking and projected adult size and overall CMN incidence. CMN was more likely in females, while maternal freckling was independently associated with smaller projected adult size. A quarter of those with CMN had a second-degree relative with CMN, noted Dr. Dyer.

Furthermore, it is estimated that 5%-30% of patients with large CMN have asymptomatic neurocutaneous melanosis (NCM). NCM symptoms – increased intracranial pressure or seizures – typically occur in the first 2 years of life, he reported. It is possible for patients to convert from asymptomatic NCM to symptomatic but it is unclear how common it is (J. Clin. Oncol. 2009;27:e136).

Occasionally NCM symptoms are temporary or controllable; however, prognosis of symptomatic NCM is guarded. MRI is sensitive for NCM in the first 4-6 months but small deposits can be missed.

In terms of risk, satellites appear to be a major risk factor for NCM in patients with CMN. If there are no satellites, the risk of NCM is very low, summarized Dr. Dyer. In addition, CMN size appears to matter more than location. Based on several studies, the risk of NCM tends to be about 20%.

It has been suggested that up to two-thirds of pediatric patients with NCM go on to develop leptomeningeal tumors. Some patients may develop symptomatic NCM as a result, reported Dr. Dyer. An estimated 50%-90% of these patients die within 3 years of symptom onset. It is also estimated that 50% develop malignant melanoma of the central nervous system (Clin. Dermatol. 2009;27:529-36) .

Many CMN improve with time, he noted. In the Great Ormond Street study, for example, the majority of untreated lesions lightened during the follow-up period (Br. J. Dermatol. 2009;160:387-92). Surgery and the presence of satellites at birth were independently associated with darkening.

Satisfaction with surgery was high for patients with CMN of less than 20 cm and for those with facial lesions. However, satisfaction was reduced with increasing projected adult size. Girls were more likely to have surgery.

Treatment seemed to increase the darkening of remaining or later-developing nevi, independent of type, timing, or nevus. Tissue expansion appeared to be associated with increased satellite development, noted Dr. Dyer. Projected adult size was associated with satellite number but not treatment type.

Childhood Melanoma

Melanoma accounts for 1%-3% of childhood malignancies. The incidence increased by 2.9% per year from 1973 to 2001 (Clin. Dermatol. 2009;27:529-36). Melanoma is seven times more common in the second decade than in the first, said Dr. Dyer. It is estimated that teens aged 15-19 years account for 73%-79% of cases.

Interestingly, there is a slight male predominance in young children that changes to a slight female predominance in older groups. Adolescent white girls with a history of ultraviolet exposure have the greatest melanoma risk, particularly on the trunk and lower extremities, he pointed out.

Approximately 30% of childhood melanomas arise with giant CMN. Lifetime risk appears to be bimodal, with the first peak in the first decade of life (usually in the first 5 years). It is estimated that 50%-70% arise before puberty. Head and neck melanomas are more common at age 1-4 years, while melanomas on the trunk are more common with increasing age. Early-life melanomas tend to be dermal with poorer outcomes. The second peak occurs in adulthood, reported Dr. Dyer.

Approximately 20% of childhood melanomas occur with other melanocytic lesions. Malignant melanomas from small CMN typically occur after puberty. These are more similar to adult malignant melanomas.

Childhood melanomas are associated with an increased incidence of amelanotic and nodular lesions. Risk factors include the following: intermittent intense sun exposure, tendency to sunburn, tendency to freckle, fair skin, blue/green eyes, blonde/red hair, xeroderma pigmentosum, giant CMN, dysplastic nevus syndrome, atypical nevi, a family history of malignant melanoma, and immunosuppression.

The risk of transformation for CMN is associated with size. Small to medium CMN (less than 20 cm) have a 1%-5% risk of transformation, while large/giant CMN (greater than 20 cm) have at least a 5%-10% risk; however, the risk may be as great as 20%.

Some studies suggest that 30%-75% of pediatric malignant melanoma originated in giant CMN, and one-third are fatal, reported Dr. Dyer. Excision does not completely eliminate the risk. In one study, 8% of patients developed extracutaneous malignant melanoma after CMN excision.

He noted that the risk of childhood melanoma is associated with immunodeficiency. The risk is six times greater if immunodeficiency is genetic in origin; the risk is four times greater if immunodeficiency is acquired.

The indications for sentinel lymph node biopsy in children are the same as in adults, he noted. Children have a higher incidence positive sentinel lymph node. However, this does not predict likelihood of recurrence or prognosis in children.

Surgical excision should use the same margins as in adults whenever possible. Thickness, ulceration, and stage at diagnosis are all prognostic factors.

Disclosures: Dr. Dyer reported having no conflicts of interest. SDEF and this news organization are owned by Elsevier.

Melanocytic nevi – spitz, congenital, and acquired – can pose diagnostic challenges for the pediatric dermatologist.

Dr. Jonathan A. Dyer offered a review of the latest literature on these pediatric melanomas at a seminar on women's and pediatric dermatology sponsored by Skin Disease Education Foundation.

Atypical Spitzoid Melanocytic Tumors (ASMT)

Data suggest that a positive sentinel lymph node biopsy (SLNB) in ASMT does not necessarily mean poor prognosis, according to Dr. Dyer, who is an assistant professor of clinical dermatology at the University of Missouri in Columbia.

Positive SLNB is not uncommon in ASMT, occurring in 28%-50% of cases. Nodal lesion morphology appears to be what matters – typical-appearing subcapsular cells versus ugly cells that replace a significant portion of the node (Am. J. Surg. Pathol. 2009;33:1386-95).

In a series of six published studies with more than 100 patients, no patient with ASMT and positive SLNB died of disease, he reported. However, follow-up was limited in many reports (median 10 months). Most malignant melanomas recur within 36 months.

In the Multicenter Selective Lymphadenectomy Trial (MSLT), the 5-year survival rate for patients younger than 19 years with malignant melanoma with a positive SLN was 68%, compared with 59% for adults.

Congenital Melanocytic Nevi (CMN)

A 19-year prospective study at Great Ormond Street Hospital in London provided a plethora of information on CMN (Br. J. Dermatol. 2009;160:143-50). The study included 349 families with CMN and 79 control families. Poor maternal health (threatened miscarriage, maternal hypertension, or severe nausea/vomiting) was associated with an increased incidence of CMN.

The researchers also found a possible positive association between maternal smoking and projected adult size and overall CMN incidence. CMN was more likely in females, while maternal freckling was independently associated with smaller projected adult size. A quarter of those with CMN had a second-degree relative with CMN, noted Dr. Dyer.

Furthermore, it is estimated that 5%-30% of patients with large CMN have asymptomatic neurocutaneous melanosis (NCM). NCM symptoms – increased intracranial pressure or seizures – typically occur in the first 2 years of life, he reported. It is possible for patients to convert from asymptomatic NCM to symptomatic but it is unclear how common it is (J. Clin. Oncol. 2009;27:e136).

Occasionally NCM symptoms are temporary or controllable; however, prognosis of symptomatic NCM is guarded. MRI is sensitive for NCM in the first 4-6 months but small deposits can be missed.

In terms of risk, satellites appear to be a major risk factor for NCM in patients with CMN. If there are no satellites, the risk of NCM is very low, summarized Dr. Dyer. In addition, CMN size appears to matter more than location. Based on several studies, the risk of NCM tends to be about 20%.

It has been suggested that up to two-thirds of pediatric patients with NCM go on to develop leptomeningeal tumors. Some patients may develop symptomatic NCM as a result, reported Dr. Dyer. An estimated 50%-90% of these patients die within 3 years of symptom onset. It is also estimated that 50% develop malignant melanoma of the central nervous system (Clin. Dermatol. 2009;27:529-36) .

Many CMN improve with time, he noted. In the Great Ormond Street study, for example, the majority of untreated lesions lightened during the follow-up period (Br. J. Dermatol. 2009;160:387-92). Surgery and the presence of satellites at birth were independently associated with darkening.

Satisfaction with surgery was high for patients with CMN of less than 20 cm and for those with facial lesions. However, satisfaction was reduced with increasing projected adult size. Girls were more likely to have surgery.

Treatment seemed to increase the darkening of remaining or later-developing nevi, independent of type, timing, or nevus. Tissue expansion appeared to be associated with increased satellite development, noted Dr. Dyer. Projected adult size was associated with satellite number but not treatment type.

Childhood Melanoma

Melanoma accounts for 1%-3% of childhood malignancies. The incidence increased by 2.9% per year from 1973 to 2001 (Clin. Dermatol. 2009;27:529-36). Melanoma is seven times more common in the second decade than in the first, said Dr. Dyer. It is estimated that teens aged 15-19 years account for 73%-79% of cases.

Interestingly, there is a slight male predominance in young children that changes to a slight female predominance in older groups. Adolescent white girls with a history of ultraviolet exposure have the greatest melanoma risk, particularly on the trunk and lower extremities, he pointed out.

Approximately 30% of childhood melanomas arise with giant CMN. Lifetime risk appears to be bimodal, with the first peak in the first decade of life (usually in the first 5 years). It is estimated that 50%-70% arise before puberty. Head and neck melanomas are more common at age 1-4 years, while melanomas on the trunk are more common with increasing age. Early-life melanomas tend to be dermal with poorer outcomes. The second peak occurs in adulthood, reported Dr. Dyer.

Approximately 20% of childhood melanomas occur with other melanocytic lesions. Malignant melanomas from small CMN typically occur after puberty. These are more similar to adult malignant melanomas.

Childhood melanomas are associated with an increased incidence of amelanotic and nodular lesions. Risk factors include the following: intermittent intense sun exposure, tendency to sunburn, tendency to freckle, fair skin, blue/green eyes, blonde/red hair, xeroderma pigmentosum, giant CMN, dysplastic nevus syndrome, atypical nevi, a family history of malignant melanoma, and immunosuppression.

The risk of transformation for CMN is associated with size. Small to medium CMN (less than 20 cm) have a 1%-5% risk of transformation, while large/giant CMN (greater than 20 cm) have at least a 5%-10% risk; however, the risk may be as great as 20%.

Some studies suggest that 30%-75% of pediatric malignant melanoma originated in giant CMN, and one-third are fatal, reported Dr. Dyer. Excision does not completely eliminate the risk. In one study, 8% of patients developed extracutaneous malignant melanoma after CMN excision.

He noted that the risk of childhood melanoma is associated with immunodeficiency. The risk is six times greater if immunodeficiency is genetic in origin; the risk is four times greater if immunodeficiency is acquired.

The indications for sentinel lymph node biopsy in children are the same as in adults, he noted. Children have a higher incidence positive sentinel lymph node. However, this does not predict likelihood of recurrence or prognosis in children.

Surgical excision should use the same margins as in adults whenever possible. Thickness, ulceration, and stage at diagnosis are all prognostic factors.

Disclosures: Dr. Dyer reported having no conflicts of interest. SDEF and this news organization are owned by Elsevier.