Practice question III answers Lung and pleural tumors

Practice question III answers

Lung and pleural tumors

© Jun Wang, MD, PhD

 

1. B. Malignant tumors composed of irregular glands lined by atypical cells are adenocarcinomas. Abscess is characterized by collection of neutrophils and other inflammatory cells in a necrotic background, but do not have glandular growth. Metastatic renal cell carcinoma does not have glandular pattern and is negative for TTF-1. Small cell carcinoma has solid nests of cells with round to oval molding nuclei and scant cytoplasm. Squamous cell carcinoma has squamous differentiation characterized by intercellular bridges and keratin pearls.

2. D. TTF-1 is usually positive in adenocarcinomas of lung. Calretinin and WT-1 are positive for mesothelioma. Chromogranin is a neuroendocrine marker that is expressed in neuroendocrine tumors, including carcinoid, small cell carcinoma, and olfactory neuroblastoma. P63 is a marker for squamous cell differentiation and is positive for squamous cell carcinoma. Vimentin is positive in all kinds of stromal cells, and renal cell carcinoma.

3. A. Mutation status of ALK and EGFR should be examined in adenocarcinomas of lung. BHD and VHL mutations are commonly seen in renal cell carcinoma. MMR mutations are seen in Lynch syndrome. NF1 and NF2 are associated with neurofibromatosis I and neurofibromatosis II. TSC1 and TSC2 are associated with tuberous sclerosis.

4. E. The tumor has squamous pearls and intercellular bridges, consistent with squamous cell carcinoma. Carcinoid tumors may form cords, nests, and glandular patterns, but do not have squamous differentiation. Large cell carcinoma is characterized by marked pleomorphism without squamous or glandular differentiation. Colon adenocarcinoma has glandular differentiation. Small cell carcinoma has solid nests of cells with round to oval molding nuclei and scant cytoplasm.

5. C. See discussion of question 2. CK20 is commonly positive for colon adenocarcinoma.

6. B. Hypercalcemia in a lung squamous cell carcinoma is usually caused by cancer production of parathyroid hormone-related protein. Calicum-sensing receptor mutation is seen in familial hypocalciuric hypercalcemia, not in the setting of lung tumors. Primary hyperparathyroidism usually has higher serum calcium with presentations of hypercalcemia, including bone pains, psychological presentations, kidney stones, and abdominal pain, etc. Secondary hyperparathyroidism usually has hypocalcemia and phosphorus retention. Vitamin D toxicity has other presentations including neurological abnormalities, GI tract presentations, etc.

7. C. Cigarette smoking is the most important risk factor for squamous cell carcinoma of lung. There is no solid evidence suggesting alcohol usage is associated with lung cancers. Asbestos exposure may be associated with lung cancers, but it is more a prominent risk factor for mesothelioma, but not the most important risk for squamous cell carcinoma and small cell carcinoma of lung. EGFR mutation is more commonly seen in adenocarcinomas of lung. UV light is associated with skin cancers, including basal cell carcinoma, squamous cell carcinoma and melanoma.

8. A. Malignant tumors composed of irregular glands lined by atypical cells are adenocarcinomas. Large cell carcinoma is characterized by marked pleomorphism without squamous or glandular differentiation. Mesothelioma may form glandular pattern but are positive for calretinin and WT1. Small cell carcinoma has solid nests of cells with round to oval molding nuclei and scant cytoplasm. Squamous cell carcinoma has squamous differentiation characterized by intercellular bridges and keratin pearls.

 

9. C. Mutation status of ALK and EGFR should be examined in adenocarcinomas of lung. Chromogranin is a neuroendocrine marker that is expressed in neuroendocrine tumors, including carcinoid, small cell carcinoma, and olfactory neuroblastoma. EB-virus infection is associated with Hodgkin lymphoma. Sputum microbiology studies are indicated for infections, not neoplasms. WT1 is positive for mesothelioma, but not indicated in this case, since negative reactivity to CK5/6 make it less likely to be mesothelioma.

 

10. C. Constriction of unilateral pupil in a patient with apex lesion is most likely Horner syndrome. It is caused by local irritation of sympathetic nerve supply. Autoantibody against postsynaptic acetylcholine receptor is seen in myasthenia gravis. Autoantibody against voltage gated calcium channel is seen in Lambert-Eaton myasthenic syndrome, a paraneoplastic syndrome associated with small cell carcinoma. CN III disrupt and metastatic tumor to right orbit are unlikely due to otherwise normal results of eye exam, including movements.

 

11. B. See discussion of question 3. WT1 mutation is seen in Wilms tumor.

 

12. A. Large cell carcinoma is characterized by marked pleomorphism without squamous or glandular differentiation. Hodgkin lymphoma have Reed Sternberg cells and are negative for cytokeratin. Mesothelioma may form glandular pattern but are positive for calretinin and WT1. Small cell carcinoma has solid nests of cells with round to oval molding nuclei and scant cytoplasm. Squamous cell carcinoma has squamous differentiation characterized by intercellular bridges and keratin pearls.

 

13. C. Large cell carcinoma is associated with cigarette smoking. EB-virus infection is associated with Hodgkin lymphoma. Also see discussion of question 7.

 

14. C. This tumor is characterized by solid nests of cells with round to oval molding nuclei and scant cytoplasm, consistent with small cell carcinoma. Small lymphocytic lymphoma/chronic lymphocytic leukemia may have similar morphology, but they are positive for CD45 and CD20, but negative for cytokeratin. Also see discussion of question 12.

 

15. D. Small cell carcinoma express neuroendocrine markers, including chromogranin, synaptophysin and CD56. CD20 is a B cell marker, that is positive in benign and malignant B cell proliferations. CD99 is positive in solitary fibrous tumor and Ewing sarcoma. P63 is a marker for squamous cell differentiation and is positive for squamous cell carcinoma. WT-1 is positive in ovarian serous neoplasms, Wilms tumor and mesothelioma.

16. E. Lambert-Eaton myasthenic syndrome is a paraneoplastic syndrome associated with small cell carcinoma. It is associated with autoantibody against voltage gated calcium channel. Autoantibody against postsynaptic acetylcholine receptor is seen in myasthenia gravis. Diabetic neuropathy commonly has symmetrical presentation involving both sensory and motor nerves. Irritation of sympathetic nerve supply is associated with Horner syndrome, characterized by unilateral pupil constriction, partial ptosis, and loss of hemifacial sweating. Muscular atrophy has reduced muscle mass.

 

17. E. These cells have abundant eosinophilic cytoplasm, atypical nuclei, focal squamous pearl formation and recognizable intercellular bridges, consistent with metastatic squamous cell carcinoma. Acute lymphadenitis has neutrophilic infiltrate, but not epithelial cells in the lymph nodes. Diffuse large B cell lymphoma is do not have squamous differentiation. Hodgkin lymphoma have Reed Sternberg cells in a background of lymphocytes and other inflammatory cells. Adenocarcinomas are composed of irregular glands lined by atypical cells, without squamous differentiation.

 

18. B. Facial swelling, distended superficial jugular veins and edematous changes involving both arms in a patient with centrally located lung mass is compatible with superior vena cava syndrome. It is caused by tumor suppression of superior vena cava. Inflammation of subcutaneous tissue usually has erythematous changes and fever as well, and tends to be localized. CHF may cause jugular vein distension, but the edematous changes are commonly seen in the lower extremities, not arms. Obstruction of lymph drainage by tumor cells usually presents as localized Peau d'orange changes, as seen in some breast cancers.

 

19. C. These tumor cells have a solid growth without typical squamous differentiation. The positive reactivities to CK5/6 and calretinin are most consistent with mesothelioma. Adenocarcinomas are composed of irregular glands lined by atypical cells, without squamous differentiation. Large cell carcinoma is characterized by marked pleomorphism without squamous or glandular differentiation. Small cell carcinoma has solid nests of cells with round to oval molding nuclei and scant cytoplasm. Squamous cell carcinoma has squamous differentiation characterized by intercellular bridges and keratin pearls. Squamous cell carcinoma does not express calretinin.

 

20. B. Asbestos exposure is the most prominent risk factor for mesothelioma. There is no solid evidence suggesting hyperglycemia or alcohol usage is associated with lung cancers or lung cancers. Cigarette smoking is the most important risk factor for many lung cancers, including squamous cell carcinoma, large cell carcinoma and small cell carcinoma. KRAS mutation may be seen in adenocarcinomas of lung.

 

 

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