cutaneous metastasis ( cm ) is an uncommon manifestation of visceral malignancies with a reported incidence of 0.79% [ 1 , 2 ] . in extremely rare cases breast cancer is the most common site for cm , followed by the lung , colorectal , renal , ovarian , and bladder cancers [ 3 , 4 ] . adenosquamous carcinoma of the gallbladder is a rare ( < 10% ) variation in gallbladder carcinoma ( gbc ) , being defined by the presence of a squamous component of 2599% [ 5 , 6 ] . the squamous variant of gbc is associated with an advanced t stage and worse prognosis [ 5 , 6 ] . gbc commonly metastasizes to the liver and regional lymph nodes , whereas skin metastasis is extremely rare . in this study , we present the case of a gbc skin metastasis that was initially confounded with a non - melanoma skin tumour . here , based on an extensive literature review , we discuss the frequency of gbc skin metastasis as well as the particularities of gallbladder adenosquamous carcinoma . in april 2011 , a 56-year - old woman presented with an enlarging red , inflamed and painful lump on her right lateral abdominal wall . initially considered as an infected epidermoid cyst , it was surgically drained . in the following 3 months , she lost 4 kg and the  infected cyst recurred twice being surgically drained both times . a cutaneous biopsy performed during the last intervention showed the presence of a squamous cell cancer and she was referred to our service . clinical examination revealed a mass in the upper right quadrant of the abdomen and a 5-cm inflamed lump at the site of the previous drainages ( fig .  1 ) . figure  1:inflamed lump on the right lateral abdominal wall initially considered as cutaneous abcess . inflamed lump on the right lateral abdominal wall a computed tomography ( ct ) scan of the abdomen and pelvis revealed a large mass involving the gallbladder ; liver segments 4b , 5 and 6 ; and the abdominal wall ( fig . figure  2:(a  c ) a ct scan revealing a large hepatic mass invading the abdominal wall . ( a  c ) a ct scan revealing a large hepatic mass invading the abdominal wall . a laparotomy was performed and , curiously , no continuity between the liver mass and the abdominal wall lesion was observed . a radical subsegmental trisegmentectomy of segments 4b , 5 and 6 of the liver along with a regional hepatoduodenal ligament lymphadenectomy and right colectomy ( fig . the abdominal wall lesion was resected with clear margins ( fig .  4 ) . figure  3:intraoperative view after resection of segments 4b , 5 and 6 of the liver along with a regional hepatoduodenal ligament lymphadenectomy . intraoperative view after resection of segments 4b , 5 and 6 of the liver along with a regional hepatoduodenal ligament lymphadenectomy . pathology analysis of the surgical specimen revealed a 12-cm adenosquamous gallbladder cancer invading the liver . the skin lesion had no continuity with the liver mass and was thus considered a cm ( pt3n0m1 ) . less than 1 month after hospital discharge , the patient noted a small enlarging and painful lump on her left shoulder . interestingly , as for the first cutaneous lesion , the squamous component was highly majority . she received six cycles of weekly gemcitabine and a ct scan showed bilateral adrenal gland metastasis . oral capecitabine was then started and 3 months later , the patient noted a 1-cm skin nodule at her left leg compatible with cm . a ct scan revealed an enlargement of the adrenal tumours , a 3-cm liver nodule and a 1.5-cm left upper lung nodule . gallbladder carcinoma is a relatively rare and lethal gastrointestinal malignancy , with the majority of cases being adenocarcinoma . primary carcinoma of the gallbladder includes the following histological types in a decreasing order of incidence : adenocarcinoma , adenosquamous carcinoma , squamous cell carcinoma and oat cell carcinoma . patients with adenosquamous cell carcinoma of the gallbladder most commonly present with a large mass replacing the gallbladder fossa . the bulky tumour is usually diagnosed at an advanced stage   with frequent invasion of the neighbouring organs , such as the liver , duodenum , stomach , colon , pancreas and extra hepatic bile ducts . the liver is the most common site of invasion , and a higher proportion of liver infiltration is observed in patients with adenosquamous carcinoma when compared with those with adenocarcinoma . gbc usually presents at an advanced stage , with metastasis in up to one - third of the patients , and a 5-year survival rate of < 5% . the overall prognosis of adenosquamous carcinoma / squamous cell carcinoma appears to be even worse with most patients dying within few months after the diagnosis . while metastatic disease is common , extra abdominal spread , as in the present case , is extremely rare . survival after the diagnosis of cm is dismal and usually < 1 month , although it has been recently described the case of a patient alive and well after 25 months following her initial diagnosis , due probably to an aggressive strategy including chemotherapy , radiotherapy and surgery for multiple metastatic recurrences . first , the patient 's skin lesion presented as a cutaneous abscess and was treated as such , and then the skin biopsy revealed a squamous cell cancer . clinical examination and cm was only suspected during surgery when no continuity between the liver tumour and the abdominal wall was identified . it is interestingly to note that recurrence first occurred at skin and adrenals , which can be probably explained by the ectodermal origin of the medullary area . in conclusion also , there is limited information in the literature about adenosquamous carcinoma of the gallbladder . this case illustrates an unusual dissemination of gbc where the correct diagnosis has been made difficult by its unusual initial presentation , and the isolated presence of the squamous cell component at skin biopsy . patient lived 10 months after resection which is superior to the mean survival reported in the literature in such cases . although resection seems to improve survival as recently published , it can not be recommended without previous multidisciplinary discussion . the key learning points of this study are as follows : 
 cm is an uncommon manifestation of visceral malignancies . adenosquamous carcinoma of the gallbladder is a rare variation in gallbladder carcinoma associated with a worse prognosis.cm can be a diagnostic trap and a high level of suspicion is necessary . adenosquamous carcinoma of the gallbladder is a rare variation in gallbladder carcinoma associated with a worse prognosis . the authors do not have any financial and personal relationships with other people or organizations that could inappropriately influence this work .
cutaneous metastasis ( cm ) is an uncommon manifestation of visceral malignancies . 
 adenosquamous carcinoma of the gallbladder is a rare variation in gallbladder carcinoma ( gbc ) , associated with worse prognosis . 
 we present the case of a 56-year - old woman who presented with an inflamed lump on her abdominal wall . computed tomography ( ct ) revealed a large mass from the gallbladder invading the abdominal wall . 
 she underwent liver resection with regional lymphadenectomy . 
 pathology analysis revealed a 12-cm pt3n0 gbc . 
 hospital discharge occurred at post - operative day 20 . 
 she recurred and died 10 months after surgery . 
 survival after the diagnosis of cm is dismal . 
 the present case was a diagnostic trap . 
 first , the patient 's skin lesion presented as a cutaneous abscess and biopsy revealed a squamous cell cancer . 
 a ct scan suggested a continuous mass involving the abdominal wall . 
 cm was only suspected during surgery when no continuity between the tumour and the abdominal wall was identified .