PMC8264542_01
(A) A dark-red hard nodule of 3 cm * 3 cm * 2.5 cm in size was found on the anterior chest, with an opening at the edge. (B) Postoperative scar. (C) The pedigree chart of the index patient (black arrow) and his family. The patient's mother had endometrial and oral mucosal cancer. (D) Colonoscopy showed irregular neoplasms protruding into the intestinal lumen 28 cm away from the anus, with the size of 3 cm * 3 cm whose irregular protrusions in the central part were brittle, hard texture, contact bleeding and covered with soiled moss.
fonc-11-681780-g001.jpg
PMC8264542_01_fonc-11-681780-g001.jpg
f1
Physical examination revealed a hard, dark-red nodule of 3 x 3 x 2.5 cm on the anterior chest that had an opening along an edge ( Figure 1A ). The family history of the patient included his mother, who had endometrial and oral mucosal cancer ( Figure 1C ). Surgical resection of the tumor was performed for diagnosis and treatment ( Figure 1B ). The neoplasms had a size of 3 x 3 cm and irregular protrusions in the central region were brittle, hard, exhibited contact bleeding, and were covered with soiled moss ( Figure 1D ).
Timeline. Treatment procedures since renal therapy. HD, hemodialysis; AKT, allograft kidney transplantation; MMF, mycophenolate mofetil; PDN, prednisone.
fonc-11-681780-g002.jpg
PMC8264542_01_fonc-11-681780-g002.jpg
f2
His allograft kidney was maintained by immunosuppressive therapy comprising tacrolimus, mycophenolate mofetil, prednisone, and Wuzhi capsule, which was used to reduce serum glutamic-pyruvic transaminase ( Figure 2 ).
(A, B) Pathological presentation of sebaceous carcinoma on the chest: (A) Tumor cells formed nests or lobules of different sizes, with clear boundary and capsule (HE x40). (B) The tumor was composed of basal-like cells and vacuolated sebaceous cells, some of which had large, hyperchromatic nuclei (HE x200). (C-F) Immunohistochemical staining for DNA mismatch repair proteins (MMR proteins MLH1, MSH2, MSH6, and PMS2) of the sebaceous carcinoma; (C) Normal nuclear expression of MLH1 protein. (D) Lack of nuclear expression of MSH2 protein. (E) Lack of nuclear expression of MSH6 protein. (F) Normal nuclear expression of PMS2 protein.
fonc-11-681780-g003.jpg
PMC8264542_01_fonc-11-681780-g003.jpg
f3
Small nests or single cancer cells had invaded the stroma, which was accompanied by an inflammatory response and granuloma ( Figures 3A, B  ). IHC also showed complete loss of MSH2 and MSH6 expression but normal MLH1 and PMS2 expression ( Figures 3C-F ).
(A, B) Histopathology showed that tumor cells were arranged in columnar and glandular tubular shape, with obvious cellular atypia as well as interstitial and muscularis mucosae infiltrate (HE x200; x400). (C-F) Immunohistochemical staining for DNA mismatch repair-related proteins (MMR proteins MLH1, MSH2, MSH6, and PMS2) of the sigmoid adenocarcinoma: (C) Normal nuclear expression of MLH1 protein. (D) Lack of nuclear expression of MSH2 protein. (E) Lack of nuclear expression of MSH6 protein. (F) Normal nuclear expression of PMS2 protein.
fonc-11-681780-g004.jpg
PMC8264542_01_fonc-11-681780-g004.jpg
f4
Histopathology showed that tumor cells were arranged in a columnar and glandular tubular shape, with obvious cellular atypia, as well as interstitial and muscularis mucosae infiltrate ( Figures 4A, B ). Furthermore, IHC also showed complete loss of MSH2 and MSH6 expression but normal MLH1 and PMS2 expression ( Figures 4C-F ).