Patient Presentation A 65-year-old woman presented with an enlarging lesion on her right forearm. She experienced no symptoms from this area on her arm. The patient was otherwise healthy with no significant medical or surgical history. Physical examination revealed a 3-cm by 4-cm hypopigmented patch with several hyperpigmented plaques dispersed within. In addition, local ulceration was identified within the lesion. No cervical, supraclavicular, axillary or epitrochlear lymphadenopathy was noted. What’s Your Diagnosis? (Turn to page 69 for an answer and for more details about the condition and this case.) About this Condition The diagnosis of melanoma is often apparent; however, detecting atypical melanomas may present a clinical challenge. In this case, this was originally thought to represent squamous cell carcinoma. Without the hallmark pigmented lesion of melanoma, cases such as this can be mistaken for a non-melanoma skin cancer or even a non-cancerous condition altogether, which can confuse or delay diagnosis. The condition is confirmed by biopsy. In this case, multiple biopsy results confirmed diagnosis of lentigo maligna melanoma (Breslow’s thickness 2.3 mm; Clark’s level IV). Immunohistochemical staining (Melan-A) was confirmative. Sentinel lymph node biopsy was negative in the affected extremity. This was followed by complete excision of the tumor with subsequent graft repair. New Melanoma Staging Information The American Joint Cancer Committee (AJCC) has recently adopted a revised melanoma TNM and staging system.1 Major revisions include the following: • observing a change in the thickness thresholds, with the use of thickness and ulceration (but not the level of invasion) in the T category, with exception of T1 • using the number of metastatic lymph nodes for definition of the N category • using the site of metastases and presence of elevated serum lactic dehydrogenase to define the M category • upstaging of patients with stage I, II and III disease in the presence of ulceration of a primary melanoma • utilizing interpretation of level of invasion for thin lesions only (<= 1.0 mm) as this has been shown to lack prognostic correlation for thicker lesions.2 • recognizing that the presence of ulceration carries an increased risk for metastasis, constituting immediate upstaging • adopting anatomic compartmentalization common in the classification of noncutaneous tumors (for example, Stage I and II represent local disease; Stage III indicates regional metastasis and Stage IV, distant metastasis) • taking into account sentinel node technology by distinguishing clinical versus pathological staging. Pathology The histopathology of lentigo maligna melanoma includes numerous characteristic features. There is an increase in the concentration of basal melanocytes that may be irregularly arranged. The epidermis is often flattened, which can aid in distinguishing from other types of melanoma. Nesting of basal melanocytes may be seen but is typically more pronounced with the onset of dermal invasion. Severe solar elastosis in the upper dermis is characteristic and may be accompanied by a bandlike inflammatory infiltrate. Treating This Condition The mainstay of treatment for melanoma remains surgical excision of the primary lesion. Margins of 0.5 cm are recommended for melanoma in situ, and 1.0 cm margins for superficial primary lesions (<= 1 mm).1 Considerable controversy exists regarding optimal excision margins for intermediate and thick melanomas. Existing data indicate that 2-cm excision margins are adequate for melanomas up to 4 mm, but there is no definitive recommendation for optimal excision margins for melanomas > 4 mm.1,3 Employing elective lymph node dissection for managing intermediate thickness melanomas has been controversial based on the argument that routine elective lymph node dissection indiscriminately subjects a number of patients with 1 mm to 4 mm melanomas to the morbidity of nodal dissection without proven benefit.4 The role of elective lymph node dissection is now being modernized by sentinel lymph node biopsy to identify nodal micrometastasis with subsequent dissection when metastasis is present in the sentinel node.4 This ensures exposure of only high-risk patients to the morbidity of surgical node dissection. Additional adjuvant therapy for high-risk patients and those with metastatic disease includes chemotherapy, hyperthermic regional perfusion for high-risk melanomas of the extremities and the immunomodulator IFN alpha-2b.4,5
Melanoma or Non-Melanoma Skin Cancer?Diagnosis: Atypical Lentigo Maligna Melanoma
Patient Presentation A 65-year-old woman presented with an enlarging lesion on her right forearm. She experienced no symptoms from this area on her arm. The patient was otherwise healthy with no significant medical or surgical history. Physical examination revealed a 3-cm by 4-cm hypopigmented patch with several hyperpigmented plaques dispersed within. In addition, local ulceration was identified within the lesion. No cervical, supraclavicular, axillary or epitrochlear lymphadenopathy was noted. What’s Your Diagnosis? (Turn to page 69 for an answer and for more details about the condition and this case.) About this Condition The diagnosis of melanoma is often apparent; however, detecting atypical melanomas may present a clinical challenge. In this case, this was originally thought to represent squamous cell carcinoma. Without the hallmark pigmented lesion of melanoma, cases such as this can be mistaken for a non-melanoma skin cancer or even a non-cancerous condition altogether, which can confuse or delay diagnosis. The condition is confirmed by biopsy. In this case, multiple biopsy results confirmed diagnosis of lentigo maligna melanoma (Breslow’s thickness 2.3 mm; Clark’s level IV). Immunohistochemical staining (Melan-A) was confirmative. Sentinel lymph node biopsy was negative in the affected extremity. This was followed by complete excision of the tumor with subsequent graft repair. New Melanoma Staging Information The American Joint Cancer Committee (AJCC) has recently adopted a revised melanoma TNM and staging system.1 Major revisions include the following: • observing a change in the thickness thresholds, with the use of thickness and ulceration (but not the level of invasion) in the T category, with exception of T1 • using the number of metastatic lymph nodes for definition of the N category • using the site of metastases and presence of elevated serum lactic dehydrogenase to define the M category • upstaging of patients with stage I, II and III disease in the presence of ulceration of a primary melanoma • utilizing interpretation of level of invasion for thin lesions only (<= 1.0 mm) as this has been shown to lack prognostic correlation for thicker lesions.2 • recognizing that the presence of ulceration carries an increased risk for metastasis, constituting immediate upstaging • adopting anatomic compartmentalization common in the classification of noncutaneous tumors (for example, Stage I and II represent local disease; Stage III indicates regional metastasis and Stage IV, distant metastasis) • taking into account sentinel node technology by distinguishing clinical versus pathological staging. Pathology The histopathology of lentigo maligna melanoma includes numerous characteristic features. There is an increase in the concentration of basal melanocytes that may be irregularly arranged. The epidermis is often flattened, which can aid in distinguishing from other types of melanoma. Nesting of basal melanocytes may be seen but is typically more pronounced with the onset of dermal invasion. Severe solar elastosis in the upper dermis is characteristic and may be accompanied by a bandlike inflammatory infiltrate. Treating This Condition The mainstay of treatment for melanoma remains surgical excision of the primary lesion. Margins of 0.5 cm are recommended for melanoma in situ, and 1.0 cm margins for superficial primary lesions (<= 1 mm).1 Considerable controversy exists regarding optimal excision margins for intermediate and thick melanomas. Existing data indicate that 2-cm excision margins are adequate for melanomas up to 4 mm, but there is no definitive recommendation for optimal excision margins for melanomas > 4 mm.1,3 Employing elective lymph node dissection for managing intermediate thickness melanomas has been controversial based on the argument that routine elective lymph node dissection indiscriminately subjects a number of patients with 1 mm to 4 mm melanomas to the morbidity of nodal dissection without proven benefit.4 The role of elective lymph node dissection is now being modernized by sentinel lymph node biopsy to identify nodal micrometastasis with subsequent dissection when metastasis is present in the sentinel node.4 This ensures exposure of only high-risk patients to the morbidity of surgical node dissection. Additional adjuvant therapy for high-risk patients and those with metastatic disease includes chemotherapy, hyperthermic regional perfusion for high-risk melanomas of the extremities and the immunomodulator IFN alpha-2b.4,5
Patient Presentation A 65-year-old woman presented with an enlarging lesion on her right forearm. She experienced no symptoms from this area on her arm. The patient was otherwise healthy with no significant medical or surgical history. Physical examination revealed a 3-cm by 4-cm hypopigmented patch with several hyperpigmented plaques dispersed within. In addition, local ulceration was identified within the lesion. No cervical, supraclavicular, axillary or epitrochlear lymphadenopathy was noted. What’s Your Diagnosis? (Turn to page 69 for an answer and for more details about the condition and this case.) About this Condition The diagnosis of melanoma is often apparent; however, detecting atypical melanomas may present a clinical challenge. In this case, this was originally thought to represent squamous cell carcinoma. Without the hallmark pigmented lesion of melanoma, cases such as this can be mistaken for a non-melanoma skin cancer or even a non-cancerous condition altogether, which can confuse or delay diagnosis. The condition is confirmed by biopsy. In this case, multiple biopsy results confirmed diagnosis of lentigo maligna melanoma (Breslow’s thickness 2.3 mm; Clark’s level IV). Immunohistochemical staining (Melan-A) was confirmative. Sentinel lymph node biopsy was negative in the affected extremity. This was followed by complete excision of the tumor with subsequent graft repair. New Melanoma Staging Information The American Joint Cancer Committee (AJCC) has recently adopted a revised melanoma TNM and staging system.1 Major revisions include the following: • observing a change in the thickness thresholds, with the use of thickness and ulceration (but not the level of invasion) in the T category, with exception of T1 • using the number of metastatic lymph nodes for definition of the N category • using the site of metastases and presence of elevated serum lactic dehydrogenase to define the M category • upstaging of patients with stage I, II and III disease in the presence of ulceration of a primary melanoma • utilizing interpretation of level of invasion for thin lesions only (<= 1.0 mm) as this has been shown to lack prognostic correlation for thicker lesions.2 • recognizing that the presence of ulceration carries an increased risk for metastasis, constituting immediate upstaging • adopting anatomic compartmentalization common in the classification of noncutaneous tumors (for example, Stage I and II represent local disease; Stage III indicates regional metastasis and Stage IV, distant metastasis) • taking into account sentinel node technology by distinguishing clinical versus pathological staging. Pathology The histopathology of lentigo maligna melanoma includes numerous characteristic features. There is an increase in the concentration of basal melanocytes that may be irregularly arranged. The epidermis is often flattened, which can aid in distinguishing from other types of melanoma. Nesting of basal melanocytes may be seen but is typically more pronounced with the onset of dermal invasion. Severe solar elastosis in the upper dermis is characteristic and may be accompanied by a bandlike inflammatory infiltrate. Treating This Condition The mainstay of treatment for melanoma remains surgical excision of the primary lesion. Margins of 0.5 cm are recommended for melanoma in situ, and 1.0 cm margins for superficial primary lesions (<= 1 mm).1 Considerable controversy exists regarding optimal excision margins for intermediate and thick melanomas. Existing data indicate that 2-cm excision margins are adequate for melanomas up to 4 mm, but there is no definitive recommendation for optimal excision margins for melanomas > 4 mm.1,3 Employing elective lymph node dissection for managing intermediate thickness melanomas has been controversial based on the argument that routine elective lymph node dissection indiscriminately subjects a number of patients with 1 mm to 4 mm melanomas to the morbidity of nodal dissection without proven benefit.4 The role of elective lymph node dissection is now being modernized by sentinel lymph node biopsy to identify nodal micrometastasis with subsequent dissection when metastasis is present in the sentinel node.4 This ensures exposure of only high-risk patients to the morbidity of surgical node dissection. Additional adjuvant therapy for high-risk patients and those with metastatic disease includes chemotherapy, hyperthermic regional perfusion for high-risk melanomas of the extremities and the immunomodulator IFN alpha-2b.4,5
