Rare clinical cases of “combined” skin carcinomas in cadaver renal allograft recipients

The most prevalent skin cancer in the transplant organ recipients is squamous cell cancer, followed by basal cell cancer. The skin cancer incidence and related mortality in the transplant organ recipient are significantly higher than those in the general population, which is to be linked with prolonged pharmaceutical immunosuppression. Multiple tumors are also typical for this patient group. The article describes two rare combinations of skin carcinomas with different histological characteristics in patients with cadaver renal allograft (CRA). Clinical case 1: A 43-year old female patient. In 2011, she was transplanted with a CRA due to end-stage renal failure caused by congenital cystic dysplasia (multicystic kidney disease), with subsequent removal of the allograft at 1.5 months after the transplantation. In 2014, she had her second CRA transplanted and until now is on immunosuppressive therapy. In 2013, the patient noticed two slowly growing masses in her right and left supraclavicular areas; they were clinically assessed as basal cell cancer and surgically resected. Histological examination of the resected skin fragments showed squamous cell carcinoma focuses in situ (Bowen's disease), with alternating superficial basalioma focuses; proliferating keratinizing squamous cell cancer with polymorphous structure, with prevailing acantholytic type, morphoeic basal cell carcinoma and basal squamous cell carcinoma were found throughout the dermal layer, up to the subcutaneous tissue. Clinical case 2: A 63-year old male patient was transplanted with CRA in 2007, due to end-stage renal failure caused by nephrolithiasis and chronic pyelonephritis. During the examination performed in 2013, a mushroom-like tumor (with a 3 cm diameter and a stipe of 1 cm in diameter, with erythematous tuberous surface) was found on the anterior neck surface, near the suprasternal notch. The tumor was surgically resected within the normal skin. Histological and immunochemical examinations showed that the mass consisted of two different tumors closely adjacent one to the other and separated by a narrow dermal layer, namely, neuroendocrine Merkel cell skin carcinoma and porocarcinoma with some signs of squamous cell and sebaceous cell differentiation.

Conclusion: The descriptions of the rare cases confirm that transplantation-related skin cancers are highly relevant. Due to continuous renewal of the tissue components that is intrinsic to this organ, and due to deterioration of the immune control over proliferation and differentiation, they are characterized by a multiplicity of histological types and an unfavorable prognosis.