Practice question answers, intestinal tumors B

Practice question answers, intestinal tumors B

© Jun Wang, MD, PhD

1. D. Tubular adenoma has tubular glands lined by columnar cells with elongated hyperchromic nuclei. Hyperplastic polyp has star-shaped lumen and no adenomatous changes (elongated hyperchromic nuclei) or significant atypia. Intramucosal adenocarcinoma is an adenocarcinoma limited to mucosa only, and has irregular glands lined by atypical cells. Sessile serrated adenoma has features of both hyperplastic polyp and adenomatous polyp. Villous adenoma is an adenomatous polyp with more than 75% of villous components.

2. A. Numerous polyps with adenomatous changes, and family history of early onset colon cancers is highly compatible with familial adenomatous polyposis. Gardner syndrome is a type of familial adenomatous polyposis, with additional manifestations including fibromatosis, osteomas, epidermal cysts, etc. Juvenile polyposis is characterized by multiple organ involvement of juvenile polyp, that has cystic dilation and inflammation. Lynch syndrome is caused by MSI gene mutation and presents with carcinomas of breast, endometrium, ovary, upper urinary tract and intestine including colon, etc., but not polyposis. Peutz-Jegher syndrome has cutaneous and mucosal macules, and/or family history and multiple Peutz-Jeghers polyps characterized by thick branching bands of smooth muscle forming a Christmas tree pattern.

3. A. APC mutation is seen in familial adenomatous polyposis. C-kit mutation is seen in gastrointestinal stromal tumor. MSI mutation is seen in Lynch syndrome, sessile serrated adenoma and certain colon cancers. SMAD4 mutation is seen in juvenile polyposis, certain colon and pancreatic adenocarcinomas. STK11 mutation is associated with Peutz-Jegher syndrome.

4. A. APC mutation is associated with beta-catenin degradation failure and subsequent nuclear translocation of active beta-catenin that promotes transcription. DNA mismatch repair is seen in MSI mutation associated colon cancers and Lynch syndrome. Abnormal p53 degradation is seen in various cancers, especially high grade malignancies. Rb1 inactivation can be seen in HPV associated malignancies, including cervical and oral cavity cancers. Telomerase activation can be seen in various neoplasms, including nasopharyngeal carcinoma and cervical cancers.

5. C. History of osteoma and current presentation of mesentery fibroma are suggestive of Gardner syndrome, a type of familial adenomatous polyposis. Bone marrow biopsy, flow cytometry of peripheral blood and iron analysis are for hematopoietic disorders including anemia and leukemia. Chest CT is indicated when intrathoracic disorders are in concerns. None of these will detect colon polyps/neoplasms.

6. D. Tubular adenoma has tubular glands lined by columnar cells with elongated hyperchromic nuclei. Hyperplastic polyp has star-shaped lumen and no adenomatous changes (elongated hyperchromic nuclei) or significant atypia. Intramucosal adenocarcinoma is an adenocarcinoma limited to mucosa only, and has irregular glands lined by atypical cells. Peutz-Jeghers polyps are characterized by thick branching bands of smooth muscle forming a Christmas tree pattern.

Villous adenoma is an adenomatous polyp with more than 75% of villous components.

7. A. Gardner syndrome is a type of familial adenomatous polyposis, with additional manifestations including fibromatosis, osteomas, epidermal cysts, etc. Inflammatory bowel diseases have relevant history and commonly have inflammatory polyps characterized by severe acute and chronic inflammation and lack of significant atypia. Juvenile polyposis is characterized by multiple organ involvement of juvenile polyp, that has cystic dilation and inflammation. Lynch syndrome is caused by MSI gene mutation and presents with carcinomas of breast, endometrium, ovary, upper urinary tract and intestine including colon, etc., but not polyposis. Peutz-Jegher syndrome has cutaneous and mucosal macules, and/or family history and multiple Peutz-Jeghers polyps characterized by thick branching bands of smooth muscle forming a Christmas tree pattern.

8. A. See discussion of question 3.

9. C. Adenocarcinoma has irregular glands lined by atypical cells. Endometrioid adenocarcinoma frequently has squamous metaplasia. In addition, rectal metastasis of endometrioid adenocarcinoma is rare. Peutz-Jeghers polyp is characterized by thick branching bands of smooth muscle forming a Christmas tree pattern. Tubular adenoma has tubular glands lined by columnar cells with elongated hyperchromic nuclei. Villous adenoma is an adenomatous polyp with more than 75% of villous components.

10. C. Primary colorectal carcinoma in a patient with history of endometrioid adenocarcinoma is suggestive of Lynch syndrome, with MSI mutations, especially in a patient younger than 50 and have history of associated tumors. APC mutation is seen in familial adenomatous polyposis, and various colorectal carcinomas. BRCA mutations are associated with various malignancies, especially those of breast and endometrium, but less likely colorectal carcinoma. SMAD4 mutation is seen in juvenile polyposis, certain colon and pancreatic adenocarcinomas. STK11 mutation is associated with Peutz-Jegher syndrome.

11. D. Lynch syndrome is caused by MSI gene mutation and presents with carcinomas of breast, endometrium, ovary, upper urinary tract and intestine including colon, etc., but not polyposis. Cowden syndrome is associated with PTEN mutation, and usually have hamartomatous or inflammatory polyps without a significantly increased risk for GI tract malignancy. Gardner syndrome is a type of familial adenomatous polyposis, with additional manifestations including fibromatosis, osteomas, epidermal cysts, etc. Juvenile polyposis is characterized by multiple organ involvement of juvenile polyp, that has cystic dilation and inflammation. Peutz-Jegher syndrome has cutaneous and mucosal macules, and/or family history and multiple Peutz-Jeghers polyps characterized by thick branching bands of smooth muscle forming a Christmas tree pattern.

12. B. See discussion of question 4.

13. C. Mucinous adenocarcinoma is characterized by abundant mucin production (mucin pools) and less than 50% of the tumor cells are signet ring cells. Juvenile polyp has cystic dilation and inflammation. Squamous cell carcinoma has squamous differentiation with intercellular bridges and/or squamous pearls. Tubular adenoma has tubular glands lined by columnar cells with elongated hyperchromic nuclei. Villous adenoma is an adenomatous polyp with more than 75% of villous components.

14. B. This patient has iron deficiency anemia. In older population, iron deficiency anemia often is caused by gastrointestinal bleeding and requires further investigation, especially when GI bleeding is confirmed by positive fecal occult blood test. Bone marrow biopsy, flow cytometry of peripheral blood and iron analysis are for hematopoietic disorders including anemia and leukemia. Folate supplementation is for megaloblastic anemia caused by folate deficiency. Iron supplementation may be used, but this patient need to identify the cause of GI bleed, that is subsequently causing anemia. Flow cytometry may be used for leukocyte phenotyping to detect neoplasms, etc, but there is no relevant evidence in this patient.

15. E. Signet ring adenocarcinoma is diagnosed when more than 50% of tumor cells have signet ring appearance. Adenocarcinoma, NOS has irregular glands lined by atypical cells. Carcinoid usually has nested or trabecular pattern and round nuclei with “salt and pepper” pattern chromatin. Hyperplastic polyp has star-shaped lumen and no adenomatous changes (elongated hyperchromic nuclei) or significant atypia. Pulmonary adenocarcinoma is usually positive for TTF-1.

16. A. Adenocarcinoma, NOS has irregular glands lined by atypical cells. Hyperplastic polyp has star-shaped lumen and no adenomatous changes (elongated hyperchromic nuclei) or significant atypia. Inflammatory polyp is characterized by severe acute and chronic inflammation, lack of significant atypia and a history of chronic inflammation such as inflammatory bowel disease. Juvenile polyp has cystic dilation and inflammation. Mucinous adenocarcinoma is characterized by abundant mucin production (mucin pools) and less than 50% of the tumor cells are signet ring cells.

17. E. This is a basaloid squamous cell carcinoma, characterized by irregular sheets of tumor cells with scant to moderate amount cytoplasm. Condyloma has koilocytes but not invasion. Melanoma is positive for S100 and HMB45. Small cell carcinoma, regardless of the location, is positive for neuroendocrine markers, such as chromogranin. Chronic lymphocytic leukemia/Small lymphocytic lymphoma is positive for pan leukocyte marker CD45, and B cell marker CD20.

18. D. Anal canal squamous cell carcinoma is likely to be associated with HPV, similar to cervical cancers. EBV is associated with various tumors, including nasopharyngeal carcinoma and certain lymphomas, such as Hodgkin lymphoma, and primary effusion lymphoma, and non-neoplastic conditions, such as infectious mononucleosis and hairy leukoplakia. HHV 2 is commonly associated with genital herpes. HIV is associated with immunocompromised status, but unlikely associated with neoplasms. Treponema pallidum causes syphilis.

19. B. Carcinoid usually has nested or trabecular pattern and round nuclei with “salt and pepper” pattern chromatin. Adenocarcinoma has irregular glands lined by atypical cells. Chronic appendicitis has chronic inflammation but not infiltrating type cords of epithelial cells. Endometriosis has benign endometrial glands and stroma, as well as hemorrhagic changes. Small cell carcinoma, regardless of the location, has sheets of crowded cells with scant cytoplasm and is positive for neuroendocrine markers, such as chromogranin.

20. E. Gelatinous material is usually suggestive of mucinous lesions. When it is seen involving peritoneum, commonly caused by mucinous neoplasms of appendix or ovary, it is diagnosed as pseudomyxoma peritonei. Carcinoid usually has nested or trabecular pattern and round nuclei with “salt and pepper” pattern chromatin, but not mucin production. Mucinous adenocarcinoma is characterized by abundant mucin production (mucin pools) and less than 50% of the tumor cells are signet ring cells, and cytological atypia. Ovarian borderline mucinous neoplasm has atypia, with or without invasion. Peritoneal carcinomatosis usually has similar morphology as serous carcinoma.

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