SKIN TUMOURS Benign lesions

SKIN TUMOURS Benign lesions

Basal cell papilloma (seborrhoeic keratosis, senile keratosis, verruca senilis) Their appearance varies from macular to soft, excrescent, warty lesions – often pigmented and hyperkeratotic – but may be flesh-coloured or pink. They are formed from the basal layer of epidermal cells and contain melanocytes. Papillary wart (verruca vulgaris) This is a benign skin tumour arising from infection with the human papillomavirus (HPV), which is also responsible for plantar warts and condylomata acuminata. Freckle (ephelis) A freckle is an area of skin that contains a normal number of melanocytes, producing an abnormally large number of melanin granules. Lentigo These are small, circumscribed pigmented macules that stem from sun damage and some systemic syndromes. Solar lentigos are commoner in fairer skins. Moles/naevi Melanocytes migrate from the neural crest to the basal epider mis during embryogenesis. When melanocytes aggregate in the dermis or at the dermoepidermal junction, they are called naevus cells. Sophie Spitz , 1910–1956, American dermatopathologist at the Memorial Sloan Kettering Cancer Center, published the first case series of ‘juvenile melanoma’ in 1948. Junctional naevus A junctional naevus is a dermoepidermal proliferation of naevus cells, visible as deeply pigmented macules or papules that occur commonly in childhood or adolescence, usually progressing to form compound or intradermal naevi with advancing age. Benign mucosal lesions tend to be junctional naevi ( Figure 45.13 ). Compound naevus This is a maculopapular, pigmented lesion that becomes most prominent during adolescence ( Figure 45.14 ). It represents a junctional proliferation of naevus cells, with nests and columns in the dermis. Intradermal naevus Intradermal naevi are faintly pigmented papules in adults that show no junctional proliferation; however, they do show a cluster of dermal melanocytes ( Figure 45.15 ). Spitz naevus These are reddish brown (occasionally deeply pigmented) nodules, previously termed ‘juvenile melanoma’ ( Figure 45.16 ). They most commonly occur on the face and legs, growing rapidly initially then remaining static or regressing. The di ff er - ential diagnosis is melanoma and excision biopsy is warranted if there is doubt as to the diagnosis. Spindle cell naevus Spindle cell naevi are dense black lesions that contain spindle cells and atypical melanocytes at the dermoepidermal junction. They are commonly seen on the thighs and a ff ect women more frequently . They may have malignant potential. Halo naevus The halo of depigmentation around any benign naevus - represents an antibody response to melanocytes. Depigmen - tation may also be a feature of a malignant melanoma. Halo naevi are associated with vitiligo ( Figure 45.17 ).

Figure 45.13 Junctional naevus (courtesy of St John’s Institute for Dermatology, London, UK).

Café-au-lait spots These are co ff ee-coloured macules of variable size (from a few millimetres to 10 /uni00A0 cm) ( Figure 45.18 ). Multiple lesions are associated with NF-1 and McCune–Albright syndromes. They are more common in dark-skinned people. Naevus spilus (speckled lentiginous naevus) These are similar in appearance to café-au-lait spots but with hyperpigmented speckles throughout ( Figure 45.19 ). They are benign lesions that are associated with various cutaneous diseases, but whose speckled appearance can be confused with malignant change. The mainstay of management is observation and serial photography as malignant transformation is rare. Donovan James McCune , 1902–1976, American pediatrician. Fuller Albright , 1900–1969, physician, Massachusetts General Hospital, Boston, MA, USA. Masao Ota , 1885–1945, Japanese dermatologist. Minoru Ito , 1892–1986, Professor of Dermatology , Tohoku University , Sendai, Honshu, Japan. Mongolian spot A Mongolian spot is a congenital blue-grey macule found on the sacral skin ( Figure 45.20 ). Pigmentation initially deepens and then regresses completely by age 7 years. Blue naevus This is a benign skin lesion that is four times more common in children, typically a ff ecting the extremities and face ( Figure 45.21 ). Naevi of Ota and Ito A naevus of Ota is a dermal melanocytic hamartoma visible as a blue or grey macule in the trigeminal V1 and V2 dermatomes. It is four times more common in women and most frequently seen in Asian and African people ( Figure 45.22 ). A naevus of Ito is characterised by dermal melanocytosis in the shoulder region and can occur simultaneously in patients with naevus of Ota ( Figure 45.23 ).

Figure 45.14 Compound naevus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.15 Intradermal naevus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.16 Spitz naevus (courtesy of St John’s Institute for Derma

tology, London, UK). Figure 45.17 Halo naevus (courtesy of St John’s Institute for Derma

tology, London, UK).

Albert Hippolyte Malherbe , 1845–1945, Professor of Histology , Anatomy and Surgery , Nantes, France.

(b) Figure 45.18 Café-au-lait spots. Note the two topographical variants: in (a) the spot has a smooth ‘coast of California’ border, whereas the upper spot in (b) has an irregular ‘coast of Maine’ border. Multiple smooth-bordered lesions are commonly associated with syndromes (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.19 Naevus spilus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.20 Mongolian spot (courtesy of St John’s Institute for Dermatology, London, UK).

SKIN TUMOURS Benign lesions

Basal cell papilloma (seborrhoeic keratosis, senile keratosis, verruca senilis) Their appearance varies from macular to soft, excrescent, warty lesions – often pigmented and hyperkeratotic – but may be flesh-coloured or pink. They are formed from the basal layer of epidermal cells and contain melanocytes. Papillary wart (verruca vulgaris) This is a benign skin tumour arising from infection with the human papillomavirus (HPV), which is also responsible for plantar warts and condylomata acuminata. Freckle (ephelis) A freckle is an area of skin that contains a normal number of melanocytes, producing an abnormally large number of melanin granules. Lentigo These are small, circumscribed pigmented macules that stem from sun damage and some systemic syndromes. Solar lentigos are commoner in fairer skins. Moles/naevi Melanocytes migrate from the neural crest to the basal epider mis during embryogenesis. When melanocytes aggregate in the dermis or at the dermoepidermal junction, they are called naevus cells. Sophie Spitz , 1910–1956, American dermatopathologist at the Memorial Sloan Kettering Cancer Center, published the first case series of ‘juvenile melanoma’ in 1948. Junctional naevus A junctional naevus is a dermoepidermal proliferation of naevus cells, visible as deeply pigmented macules or papules that occur commonly in childhood or adolescence, usually progressing to form compound or intradermal naevi with advancing age. Benign mucosal lesions tend to be junctional naevi ( Figure 45.13 ). Compound naevus This is a maculopapular, pigmented lesion that becomes most prominent during adolescence ( Figure 45.14 ). It represents a junctional proliferation of naevus cells, with nests and columns in the dermis. Intradermal naevus Intradermal naevi are faintly pigmented papules in adults that show no junctional proliferation; however, they do show a cluster of dermal melanocytes ( Figure 45.15 ). Spitz naevus These are reddish brown (occasionally deeply pigmented) nodules, previously termed ‘juvenile melanoma’ ( Figure 45.16 ). They most commonly occur on the face and legs, growing rapidly initially then remaining static or regressing. The di ff er - ential diagnosis is melanoma and excision biopsy is warranted if there is doubt as to the diagnosis. Spindle cell naevus Spindle cell naevi are dense black lesions that contain spindle cells and atypical melanocytes at the dermoepidermal junction. They are commonly seen on the thighs and a ff ect women more frequently . They may have malignant potential. Halo naevus The halo of depigmentation around any benign naevus - represents an antibody response to melanocytes. Depigmen - tation may also be a feature of a malignant melanoma. Halo naevi are associated with vitiligo ( Figure 45.17 ).

Figure 45.13 Junctional naevus (courtesy of St John’s Institute for Dermatology, London, UK).

Café-au-lait spots These are co ff ee-coloured macules of variable size (from a few millimetres to 10 /uni00A0 cm) ( Figure 45.18 ). Multiple lesions are associated with NF-1 and McCune–Albright syndromes. They are more common in dark-skinned people. Naevus spilus (speckled lentiginous naevus) These are similar in appearance to café-au-lait spots but with hyperpigmented speckles throughout ( Figure 45.19 ). They are benign lesions that are associated with various cutaneous diseases, but whose speckled appearance can be confused with malignant change. The mainstay of management is observation and serial photography as malignant transformation is rare. Donovan James McCune , 1902–1976, American pediatrician. Fuller Albright , 1900–1969, physician, Massachusetts General Hospital, Boston, MA, USA. Masao Ota , 1885–1945, Japanese dermatologist. Minoru Ito , 1892–1986, Professor of Dermatology , Tohoku University , Sendai, Honshu, Japan. Mongolian spot A Mongolian spot is a congenital blue-grey macule found on the sacral skin ( Figure 45.20 ). Pigmentation initially deepens and then regresses completely by age 7 years. Blue naevus This is a benign skin lesion that is four times more common in children, typically a ff ecting the extremities and face ( Figure 45.21 ). Naevi of Ota and Ito A naevus of Ota is a dermal melanocytic hamartoma visible as a blue or grey macule in the trigeminal V1 and V2 dermatomes. It is four times more common in women and most frequently seen in Asian and African people ( Figure 45.22 ). A naevus of Ito is characterised by dermal melanocytosis in the shoulder region and can occur simultaneously in patients with naevus of Ota ( Figure 45.23 ).

Figure 45.14 Compound naevus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.15 Intradermal naevus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.16 Spitz naevus (courtesy of St John’s Institute for Derma

tology, London, UK). Figure 45.17 Halo naevus (courtesy of St John’s Institute for Derma

tology, London, UK).

Albert Hippolyte Malherbe , 1845–1945, Professor of Histology , Anatomy and Surgery , Nantes, France.

(b) Figure 45.18 Café-au-lait spots. Note the two topographical variants: in (a) the spot has a smooth ‘coast of California’ border, whereas the upper spot in (b) has an irregular ‘coast of Maine’ border. Multiple smooth-bordered lesions are commonly associated with syndromes (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.19 Naevus spilus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.20 Mongolian spot (courtesy of St John’s Institute for Dermatology, London, UK).

SKIN TUMOURS Benign lesions

Basal cell papilloma (seborrhoeic keratosis, senile keratosis, verruca senilis) Their appearance varies from macular to soft, excrescent, warty lesions – often pigmented and hyperkeratotic – but may be flesh-coloured or pink. They are formed from the basal layer of epidermal cells and contain melanocytes. Papillary wart (verruca vulgaris) This is a benign skin tumour arising from infection with the human papillomavirus (HPV), which is also responsible for plantar warts and condylomata acuminata. Freckle (ephelis) A freckle is an area of skin that contains a normal number of melanocytes, producing an abnormally large number of melanin granules. Lentigo These are small, circumscribed pigmented macules that stem from sun damage and some systemic syndromes. Solar lentigos are commoner in fairer skins. Moles/naevi Melanocytes migrate from the neural crest to the basal epider mis during embryogenesis. When melanocytes aggregate in the dermis or at the dermoepidermal junction, they are called naevus cells. Sophie Spitz , 1910–1956, American dermatopathologist at the Memorial Sloan Kettering Cancer Center, published the first case series of ‘juvenile melanoma’ in 1948. Junctional naevus A junctional naevus is a dermoepidermal proliferation of naevus cells, visible as deeply pigmented macules or papules that occur commonly in childhood or adolescence, usually progressing to form compound or intradermal naevi with advancing age. Benign mucosal lesions tend to be junctional naevi ( Figure 45.13 ). Compound naevus This is a maculopapular, pigmented lesion that becomes most prominent during adolescence ( Figure 45.14 ). It represents a junctional proliferation of naevus cells, with nests and columns in the dermis. Intradermal naevus Intradermal naevi are faintly pigmented papules in adults that show no junctional proliferation; however, they do show a cluster of dermal melanocytes ( Figure 45.15 ). Spitz naevus These are reddish brown (occasionally deeply pigmented) nodules, previously termed ‘juvenile melanoma’ ( Figure 45.16 ). They most commonly occur on the face and legs, growing rapidly initially then remaining static or regressing. The di ff er - ential diagnosis is melanoma and excision biopsy is warranted if there is doubt as to the diagnosis. Spindle cell naevus Spindle cell naevi are dense black lesions that contain spindle cells and atypical melanocytes at the dermoepidermal junction. They are commonly seen on the thighs and a ff ect women more frequently . They may have malignant potential. Halo naevus The halo of depigmentation around any benign naevus - represents an antibody response to melanocytes. Depigmen - tation may also be a feature of a malignant melanoma. Halo naevi are associated with vitiligo ( Figure 45.17 ).

Figure 45.13 Junctional naevus (courtesy of St John’s Institute for Dermatology, London, UK).

Café-au-lait spots These are co ff ee-coloured macules of variable size (from a few millimetres to 10 /uni00A0 cm) ( Figure 45.18 ). Multiple lesions are associated with NF-1 and McCune–Albright syndromes. They are more common in dark-skinned people. Naevus spilus (speckled lentiginous naevus) These are similar in appearance to café-au-lait spots but with hyperpigmented speckles throughout ( Figure 45.19 ). They are benign lesions that are associated with various cutaneous diseases, but whose speckled appearance can be confused with malignant change. The mainstay of management is observation and serial photography as malignant transformation is rare. Donovan James McCune , 1902–1976, American pediatrician. Fuller Albright , 1900–1969, physician, Massachusetts General Hospital, Boston, MA, USA. Masao Ota , 1885–1945, Japanese dermatologist. Minoru Ito , 1892–1986, Professor of Dermatology , Tohoku University , Sendai, Honshu, Japan. Mongolian spot A Mongolian spot is a congenital blue-grey macule found on the sacral skin ( Figure 45.20 ). Pigmentation initially deepens and then regresses completely by age 7 years. Blue naevus This is a benign skin lesion that is four times more common in children, typically a ff ecting the extremities and face ( Figure 45.21 ). Naevi of Ota and Ito A naevus of Ota is a dermal melanocytic hamartoma visible as a blue or grey macule in the trigeminal V1 and V2 dermatomes. It is four times more common in women and most frequently seen in Asian and African people ( Figure 45.22 ). A naevus of Ito is characterised by dermal melanocytosis in the shoulder region and can occur simultaneously in patients with naevus of Ota ( Figure 45.23 ).

Figure 45.14 Compound naevus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.15 Intradermal naevus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.16 Spitz naevus (courtesy of St John’s Institute for Derma

tology, London, UK). Figure 45.17 Halo naevus (courtesy of St John’s Institute for Derma

tology, London, UK).

Albert Hippolyte Malherbe , 1845–1945, Professor of Histology , Anatomy and Surgery , Nantes, France.

(b) Figure 45.18 Café-au-lait spots. Note the two topographical variants: in (a) the spot has a smooth ‘coast of California’ border, whereas the upper spot in (b) has an irregular ‘coast of Maine’ border. Multiple smooth-bordered lesions are commonly associated with syndromes (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.19 Naevus spilus (courtesy of St John’s Institute for Dermatology, London, UK). Figure 45.20 Mongolian spot (courtesy of St John’s Institute for Dermatology, London, UK).