case_images: PMC10624937_01
case_images: Findings of CT and lower endoscopic examination. a The nodule of the right lung is regarded as a metastasis of renal cell carcinoma. b The tumor of the left rib that was treated by radiation therapy in 2014 is also regarded as a metastasis of renal cell carcinoma. c The edema of the intestine is particularly evident at the ileocecum. d Scattered erosions are seen at the descending and sigmoid colon.
case_images: crg-2023-0017-0001-531066_F01.jpg
case_images: PMC10624937_01_crg-2023-0017-0001-531066_F01.jpg
case_images: F1
case_images: C-reactive protein (ranged about 2.0-8.0 mg/dL) had been diagnosed by the hemodialysis clinic before this hospitalization. Computed tomography revealed the known metastatic tumors (rib, lung) and intestinal edema (Fig. 1a, b). This finding was particularly evident at the ileocecum (Fig. 1c). Lower endoscopic examination revealed scattered erosions at the descending and sigmoid colon (Fig. 1d).
case_images: Histological findings of the biopsied specimens from the colonic erosion. a Acidophilic and homogeneous amorphous material is identified in the submucosa (H&E staining). b This material shows positive staining for DFS and is compatible as an amyloid protein. c Immunohistochemically, the amyloid protein shows positive staining for SAA. DFS, direct fast scarlet; H&E, hematoxylin and eosin.
case_images: crg-2023-0017-0001-531066_F02.jpg
case_images: PMC10624937_01_crg-2023-0017-0001-531066_F02.jpg
case_images: F2
case_images: To investigate the cause of intractable diarrhea, biopsies from colonic erosions were done and hematoxylin and eosin and direct fast scarlet staining finding showed amyloid deposition in the submucosal layer of the colonic mucosa with erosion (Fig. 2a, b). Immunohistochemically, the amyloid protein was positive for SAA (Fig. 2c) and negative for kappa and lambda-light chain, beta2 microglobulin, prealbumin (data are not shown).
case_images: Finding of autopsy. a Severe inflammation such as erosions, ulcers are seen at the large intestine macroscopically. A, ascending; T, transverse; D, descending; S, sigmoid; R, rectum). These findings are evident at the ileocecum. b The left rib tumor consists of clear cell carcinoma and is histologically compatible as metastasis of renal cell carcinoma. c-e The histological findings of erosion of large intestine show the same pattern as the biopsied specimens. Amyloid deposition in the submucosal layer is shown under the erosions. This amyloid protein is positive staining for SAA (c H&E; d DFS; e SAA). DFS, direct fast scarlet; H&E, hematoxylin and eosin.
case_images: crg-2023-0017-0001-531066_F03.jpg
case_images: PMC10624937_01_crg-2023-0017-0001-531066_F03.jpg
case_images: F3
case_images: Autopsy findings revealed severe macroscopic inflammation with erosions and ulcers at the ileocecum (Fig. 3a). These amyloid proteins showed the same immunohistochemical findings as the biopsied specimens (positive for SAA, negative for kappa and lambda-light chain, beta2 microglobulin, prealbumin) (Fig. 3c-e). All these tumors consisted of clear cell carcinoma and were compatible as metastasis of renal cell carcinoma histologically (Fig. 3b).