WBR0930
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| Author | PageAuthor::William J Gibson (Reviewed by Serge Korjian) |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology, MainCategory::Pharmacology |
| Sub Category | SubCategory::Hematology |
| Prompt | Prompt::A 35-year-old man is treated for acute promyelocytic leukemia with a sustained course of arsenic trioxide and All-trans-retinoic acid (ATRA). If he develops a secondary malignancy due to this therapy, which of the following is most probable? |
| Answer A | AnswerA::Gastric cancer |
| Answer A Explanation | AnswerAExp::Gastric cancer can occur as a result of nistrosamine exposure. Nitrosamines are carcinogenic chemical compounds present in various foods, notably smoked meats. |
| Answer B | AnswerB::Leukemia |
| Answer B Explanation | AnswerBExp::Leukemia can occur as a result of previous genotoxic chemotherapy, such as alkylating agents. |
| Answer C | AnswerC::Transitional cell carcinoma of the bladder |
| Answer C Explanation | AnswerCExp::Transitional cell carcinoma of the bladder is associated with previous exposure to napthylamine compounds (used in the manufacture of aniline synthetic dyes). |
| Answer D | AnswerD::Hepatocellular carcinoma |
| Answer D Explanation | AnswerDExp::Hepatocellular carcinoma is caused by exposure to aflatoxin. |
| Answer E | AnswerE::Angiosarcoma |
| Answer E Explanation | AnswerEExp::Angiosarcoma is a potential late complication of exposure to arsenic. |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::Acute promyelocytic leukemia (APML) is a rare subset of acute myeloid leukemia (AML). APML is characterized by a chromosomal translocation involving the retinoic acid receptor-alpha gene on chromosome 17 (RARA). APML cells undergo a differentiation arrest, which can be reversed with all-trans retinoic acid. Arsenic is thought to act by inhibiting the enzyme thioredoxin reductase, an enzyme that is essential for cell growth and survival and that is upregulated in APML cells. Histologically, APML is notable for leukemic cells containing rod-like cytoplasmic inclusions called “Auer rods”. Treatment of APML can precipitate release of these inclusions causing disseminated intravascular coagulopathy (DIC). Prolonged therapy with arsenic trioxide, a known carcinogenic agent, increases the risk of certain cancer particularly squamous cell carcinoma of the skin as well as angiosarcoma of the liver. Educational Objective: Angiosarcoma is a potential late complication of exposure to arsenic. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Cancer, WBRKeyword::Chemotherapy, WBRKeyword::Side effect, WBRKeyword::Leukemia, WBRKeyword::Acute promyelocytic leukemia, WBRKeyword::Toxin |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |