seborrheic keratosis ( sk ) is an extremely common benign epidermal proliferative lesion , which is prevalent in all races .
most lesions are found on the trunk , face , scalp , and the extremities , although they can occur anywhere on the body except the palms and soles .
the most common appearance is that of a very superficial verrucous plaque which appears to be stuck on the surface , varying from dirty yellow to black in color .
giant lesions are very rare , and their location on the genital area is rarer still , with no more than 10 published cases .
we report here a case of multiple giant sk lesions located on the genitals and the adjacent areas .
a 59-year - old man presented with large dark coloured growths over his lower abdomen , genitalia and the adjoining areas of 10 years duration .
the disease started as small elevations over the penis and left groin . over the next few years , new lesions appeared over the adjacent areas and grew in size to attain the present dimensions .
the patient initially had local discomfort , occasional pain and irritation over the affected sites , but he was otherwise in good health .
examination revealed multiple , brownish black to black nodules , plaques , and tumors with lobulated , irregular , greasy surface [ figure 1 ] . in some areas , the lesions had erythematous moist erosions over the surface [ figure 2 ] .
the lesions were distributed over the pubic area , penis , scrotum , groins , upper thigh , perineum , and the perianal areas .
some lesions were discrete , while the others were confluent , giving rise to large plaques .
histopathological examination of multiple biopsy specimens showed similar features of hyperkeratosis , papillomatosis and acanthosis with proliferation of basaloid cells containing multiple horn cysts [ figure 3 ] .
large , blackish growths with verrucous , lobulated surface over the pubis , penis , scrotum , groin , and upper thigh large , warty , lobulated tumors over the perineum , groin and upper thigh .
some areas are reddish , with eroded surface histopathology showing hyperkeratosis , acanthosis with basaloid cells , papillomatosis and horn cysts within the acanthotic epidermis ( h and e , 100 ) based on the clinical and histopathological findings , a diagnosis of giant seborrhoeic keratoses was made and the patient was referred to plastic surgery department for further management .
sks are common benign lesions , which usually present with multiple pigmented papules and plaques with a  stuck on  appearance .
lesions are rarely more than 3 cm in diameter and occur most often on trunk , face , and extremities , particularly over the sun exposed areas . the lesions tend to increase in number and size with advancing age .
morphologic variants of sk include the common flat type , skin tag like , stucco keratosis , dermatosis papulosa nigra , inverted follicular keratosis , and melanoacanthoma .
large , often polypoidal lesions have been reported to occur on the genital / perigenital area on rare occasions .
multiple giant pedunculated lesions over the penis of 20 years duration , perianal polypoidal lesions , and large perigenital lesions complicated by myiasis have been reported in the past .
however , such extensive involvement as in our case with lesions over the pubic area , genitals , scrotum , perineum , thigh , and perianal areas has not been documented previously .
giant sk may have to be differentiated from condyloma acuminata , melanoma , and buschke lwenstein tumor .
condyloma acuminata or genital warts usually involve the glans and shaft of the penis and the perianal area , but may affect the adjoining skin .
the lesions are usually skin colored to brownish , have a rough surface with filiform projections and lack the greasiness of the surface typical of sk .
buschke lwenstein tumor is a locally aggressive verrucous carcinoma that typically starts on the prepuce and slowly grows into a cauliflower like mass .
melanomas are darkly pigmented , show irregularity of border and color with frequent ulceration , bleeding and local lymph node involvement .
several histological subtypes are generally recognized : acanthotic , hyperkeratotic , adenoid ( reticulated ) , clonal , irritated , inverted follicular keratosis , and melanoacanthoma . of these , the acanthotic subtype is the most common variant .
the acanthotic type , as in our case , demonstrates hyperkeratosis , marked acanthosis with basaloid cells , papillomatosis and presence of horn cysts or pseudocysts .
the cause of genital sk is as yet unknown , but there may be a possible role of chronic friction
. formation of in situ carcinoma and basal cell carcinoma has been documented rarely in acanthotic sk .
the common flat type of sk may be left alone or may be treated with liquid nitrogen cryotherapy , curettage , shave excision , or light electrodessication .
the large and extensive lesions as in our case , however , need surgical excision and plastic reconstruction .
 seborrheic keratosis ( sk ) is a very common benign epidermal proliferation that is prevalent in all races . 
 most commonly occurring on the trunk , face , scalp , and the extremities , they can occur anywhere on the body except the palms and soles . 
 the most common appearance is that of a very superficial verrucous plaque which appears to be stuck on the surface . 
 giant lesions are very rare , and their location on the genital area is rarer still . 
 we report here a case of multiple giant sk lesions in a 59-year - old man . 
INTRODUCTION
CASE REPORT
DISCUSSION