ABSTRACT Introduction McKittrick-Wheelock syndrome is a rare entity characterized by chronic diarrhea, acute kidney injury, and hydroelectrolytic imbalance associated with a large rectal tumor, frequently a villous adenoma. Case report A 69-year-old male with chronic diarrhea with mucus. He underwent a colonoscopy with biopsies, reporting adenocarcinoma of the rectum in situ, and underwent a robot assisted intersphincteric resection with colo-anal anastomosis and a protecitive ileostomy. Discussion Described in 1954, this syndrome is manifested by electrolyte imbalance and acute renal injury secondary to diarrhea associated with a rectal villous adenoma, often with long lasting symptoms. The most frequent symptom being watery diarrhea with mucus. The definitive treatment consists of surgical resection. Conclusion Although this is a rare pathology, it should be considered as a differential diagnosis in cases of chronic diarrhea associated with water and electrolyte disorders.

Abstract Introduction Inverse psoriasis affects the skin of flexural areas, such as the groin, axillae, umbilicus, intergluteal fold, and external genitalia. Clinical Case We herein report the case of a man who presented with anal pruritus and, upon physical examination, a perianal dermatosis was found, which was characterized by erythematous plaques, with fine scaling. The case was initially managed with zinc oxide, and when no improvement was observed, we decided to take an incisional biopsy, which indicated histological changes suggestive of psoriasiform dermatitis. Discussion Inverse psoriasis affects 3% to 7% of patients with psoriasis, and it manifests with erythematous plaques without the classic scaling appearance. The skin in these areas is susceptible to maceration, irritation, and ulceration, which alter the classic clinical picture. It may present with typical lesions or, less frequently, in isolation in the anogenital region. In the anogenital presentation only, the diagnosis should be made by biopsy, looking for the classic histopathological features of psoriasis. As for the first-line treatment, low- or medium-potency topical steroids are used for short periods of time; the second-line treatment is with emollients and tar-based products; and the third-line treatment uses an immunomodulator. Conclusion This presentation is infrequent, and it requires a high index of suspicion for the diagnosis, always supported by biopsies, in search of the classic histopathological features of psoriasis.