目的：描述個案口服erlotinib與血小板減少症（thrombocytopenia）的關聯性。
個案總結：一位72歲的男性病人，肺部右中葉肺腺癌，依據國際肺癌研究協會的肺癌分級(IASLC：International Association for the Study of Lung Cancer)，為T2N3M1（T: primary tumor，N: regional lymph node，M: distant metastasis），第4期合併有腦部轉移，曾接受一系列化學治療，使用erlotinib治療，每日一次，口服150 mg藥物治療約兩個月後，出現血小板減少症，停止服用 erlotinib及給予輸注血小板，血小板數量逐漸回升。
討論：在口服 erlotinib 治療一段時間，病人發生血小板減少症，停止服用 erlotinib之後， 血小板數量有回升現象。在這段時間內，似乎沒有其他藥品會導致個案血小板減少症，因此懷疑可能是erlotinib導致個案血小板減少症。
結論：此個案無法排除服用erlotinib與血小板減少症的關聯性，血小板減少症的臨床症狀，容易被忽略，因而未能及時作適當的處理，最後可能因血小板數量持續減少，增加出血症狀而危及生命。因此醫護人員應注意erlotinib與血小板減少症的關聯性。如果病人有出現血小板減少症時，當懷疑可能與服用erlotinib有關，應立即停止服用erlotinib，並予以嚴密監控病人病情。

OBJECTIVE: To describe a case of thrombocytopenia associated  with the administration of erlotinib.
CASE SUMMARY: A 72-year-old man presented with lung cancer adenocarcinoma, RML right middle lobe , T2N3M1 T: primary tumor N: regional lymph node M: distant metastasis , stage 4, with brain metastasis. The patient received a series chemotherapy and erlotinib 150 mg daily these days.He occured thrombocytopenia after administrating about 2 months of erlotinib. Erlotinib was discontinued and infusion platelet 12 U, then the platelet count increased gradually.
DISCUSSION: The onset of thrombocytopenia after administration of erlotinib, the platelet count increased after discontinuation of the drug, and the fact that no other medicines were introduced during this time lead us to believe that was likely thrombocytopenic response to erlotinib.
CONCLUSIONS: Erlotinib-associated thrombocytopenia cannot be ruled out in the patient reported here. Clinicians should be aware of this adverse event when patient is taking erlotinib.