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pyoderma gangrenosum ( pg ) is a rare sterile inflammatory neutrophilic dermatosis characterized by recurrent painful ulcerations .
although the etiology is unclear , it is often associated with inflammatory bowel disease , rheumatoid arthritis or malignancies .
recently , this condition was included in the group of cutaneous autoinflammatory disorders , characterized by defects in the innate immune response .
the name suggests an infectious agent but autoimmune mechanisms , neutrophil dysfunction , and disturbance of cellular immunity seem to be implicated .
the accumulation of neutrophils in the skin lesions , similar with sweet syndrome ( acute febrile neutrophilic dermatosis ) supporting the inclusion of pg within the spectrum of neutrophilic dermatoses .
the frequency of pathergy ( development of new lesions or aggravation of existing ones following local injuries ) suggests altered inflammatory responses to nonspecific stimuli .
the widely accepted hypothesis is that pg has a complex and multifactorial pathogenesis , including genetic predisposition , paraneoplastic or para - immune phenomena , and undefined infectious agents [ 4 , 5 ] .
the most common clinical classification includes four major types : ulcerative , pustular , bullous , and vegetative [ 6 , 7 ] .
other particular forms have also been described : peristomal , genital , mucosal , extracutaneous , and postoperative [ 811 ] .
herein , the authors present a patient with postoperative pg in association with renal cell carcinoma and chronic lymphocytic leukemia .
the patient also suffered from stable chronic lymphocytic leukemia treated with rituximab and hypothyroidism under substitution with l - thyroxine .
five days after nephrectomy , a progressive painful ulceration developed rapidly at the site of incision .
1pyoderma gangrenosum : a extensive ulceration at the site of incision with violaceous borders at the periphery ; b the ulceration after 12  days of corticotherapy pyoderma gangrenosum : a extensive ulceration at the site of incision with violaceous borders at the periphery ; b the ulceration after 12  days of corticotherapy the patient became febrile and his white blood cells ( wbc ) rose from 6,100 to 56,000/mm .
c - reactive protein ( crp ) levels increased from 1.4 to 259  mg / l . at this point , a wound infection was suspected .
he was empirically treated with antibiotics ( ciprofloxacin , then imipenem and doxycycline ) but its condition progressed relentlessly .
however , blood culture was positive for staphylococcus haemolyticus , and imipenem was changed for vancomycin . despite broad - spectrum antibiotics , there was a sustained expansion of the skin lesion .
a biopsy specimen of the edge of the ulceration showed a phlegmonous nonspecific inflammation without being able to differentiate between a necrotizing wound infection and pg .
histology showed a chronic granulomatous inflammation with subepithelial edema . a minimal focal inflammatory reaction affecting small and medium - sized vessels
.  4 ) and epstein  barr virus latent membrane protein-1 oncogene ( ebv - lmp ) were negative.fig . 
2histology : haematoxylin and eosin staining of the vital edge of the dermal debridement with pronounced phlegmonous and granulomatous nonspecific inflammation approximating the deep dermis and the subcutaneous fat tissuefig . 
3immunohistochemistry : the inflammatory infiltrate mostly consisted of myeloperoxidase positive granulocytes with only few concomitant lymphocytesfig . 
4immunohistochemistry : no indication of an appreciable cd79a positive b - lymphoid cell population histology : haematoxylin and eosin staining of the vital edge of the dermal debridement with pronounced phlegmonous and granulomatous nonspecific inflammation approximating the deep dermis and the subcutaneous fat tissue immunohistochemistry : the inflammatory infiltrate mostly consisted of myeloperoxidase positive granulocytes with only few concomitant lymphocytes immunohistochemistry : no indication of an appreciable cd79a positive b - lymphoid cell population taking into account the medical history , clinical features , histology , and lack of pathogens , the diagnosis of postoperative pg within chronic lymphocytic leukemia and renal cell carcinoma was made . the diagnosis of bacteremia with s. haemolyticus was also made .
therapy with high - dose prednisolone ( 250  mg / day ) was initiated .
standard wound care consisted of polyhexanide applications and enzymatic debridement of necrotic tissue . after 2  weeks of treatment
postoperative pg was first described by cullen in 1924 ; therefore , it is also known as postoperative progressive gangrene of cullen . this entity
this form of pg begins as multiple small ulcerations several days to weeks after apparently normal healing .
it has been reported most often in association with abdominal and breast surgery , but it can complicate any invasive procedure .
typical presentation is a primarily sterile ulcer several days after surgery , with rapid progression , lack of response to antibiotics and removal of necrotic tissue , and prompt healing after immunosuppressive agents .
this case is an excellent example of postoperative pg affecting a patient with two different types of malignancies simultaneously .
the pg lesions have been initiated by surgical procedure , but the patient s status clearly played a significant etiopathogenetic role .
the frequency of association between pg and malignancies is approximately 7% ( in particular leukemia ) .
more than half of all reported patients with pg in association with leukemia , presented acute myeloblastic leukemia with granulocytic maturation ( m2 ) , but chronic lymphocytic leukemia was also identified [ 17 , 18 ] . to the author s knowledge ,
pg was not reported in association with renal cell carcinoma , but it was reported in another patient receiving maintenance rituximab therapy for lymphoma .
it depends upon a combination of clinical presentation , histology , history of underlying diseases , and exclusion of other conditions .
given the nonspecific histological findings and a positive blood culture for s. haemolyticus , it was very difficult to exclude a necrotizing wound infection .
the leukocytosis in the absence of lymphocytosis can not be explained by chronic lymphocytic leukemia or bacteremia .
50,000/mm ) in the absence of hematologic malignancies have been reported [ 20 , 21 ] . despite a positive blood culture
, the wound culture remained negative and the skin lesion responded to corticosteroids instead of antibiotics .
similar features can be found in fournier s gangrene , a rare but life threatening disease affecting patients with comorbidities , especially diabetes mellitus and alcoholism .
it is a fulminant form of infective necrotising fasciitis affecting the perineal , genital , or perianal regions .
wound culture is commonly positive for at least three organisms , including aerobes and anaerobes .
fournier s gangrene requires an aggressive approach , including broad spectrum antibiotics , hemodynamic stabilization , and surgical debridement .
it was highlighted that early surgical debridement is the first therapeutic intervention and has a major impact on the prognosis .
other diseases to be considered in the differential diagnosis are malignancy , vasculitis , sweet syndrome , or factitious ulcerations .
in conclusion , faced with postoperative necrotizing ulceration resistant to correctly administered antibiotics , pg must be considered in any case of apparently delayed wound healing .
since the most important findings suggestive for pg are painful ulcers with rapid outgrowth and undermined , violaceous borders in absence of infection , the diagnosis must not be guided primarily by histology and early advice of a dermatologist is recommended .
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introductionpyoderma gangrenosum ( pg ) is a rare sterile neutrophilic dermatosis characterized by painful recurrent ulcerations . 
 it is frequently associated with inflammatory bowel disease , rheumatoid arthritis , or malignancies . 
 pg is a diagnosis of exclusion , and it is based on clinical presentation , histology , history of an underlying disease , and exclusion of other causes of ulceration.case reportthe authors report a 62-year - old male who developed a nonhealing ulcer at the site of incision following nephrectomy for renal cell carcinoma . 
 past medical history included chronic lymphocytic leukemia treated with rituximab . 
 histology of the skin lesion showed a phlegmonous nonspecific inflammation without being able to differentiate between a necrotizing wound infection and pg . 
 the patient s condition was initially diagnosed as an infectious process and treated accordingly . 
 after unsuccessful results with systemic antibiotics , high - dose corticosteroids induced prompt healing of the wound . on these bases 
 , the diagnosis of postoperative pg within chronic lymphocytic leukemia and renal cell carcinoma was made.conclusionfaced with postoperative necrotizing ulceration resistant to correctly administered antibiotics , pg must be considered . in such condition 
 , the diagnosis must not be guided primarily by histology and early advice of a dermatologist is recommended .