The patient (female/46) was diagnosed simultaneously with gastric cancer and Krukenberg tumor in February 2010. She received chemotherapy with a regimen of oxaliplatin/fluorouracil/leucovorin combination (mFOLFOX6). Treatment was repeated in two-week intervals. Premedication for antiemesis composed of dexamethasone 8 mg on days 1, 2, and 3 and serotonin 5-HT3 antagonist (ramosetron) on days 1, 2, and 3. She completed 12 cycles of chemotherapy with a regimen of mFOLFOX6 in August, 2010. Two months after the completion of chemotherapy, her cancer progressed in October, 2010. She began to receive a second line of chemotherapy with a regimen of irinotecan/fluorouracil/leucovorin (mFOLFIRI) biweekly. The prophylactic antiemetic regimen was the same as the previous chemotherapy. After the second line of chemotherapy, we decided to quit chemotherapy and focus on supportive care because of a newly developed multiple-bone metastasis. She began to complain of dyspnea and cough without fever 12 days after 4th cycle of chemotherapy. Respiratory sound was normal without crackle or wheezing. Arterial blood gas analysis showed hypoxia and hypocapnia. There was increased reticular opacification on both lower lobes of the lungs on patient's chest X-ray. The chest computed tomography (CT) had a patchy ground-glass appearance. We promptly started treatment of PCP with intravenous sulfamethoxazole/trimethoprim. Prednisolone was added to decrease inflammation. The dyspnea and cough resolved quickly from the beginning of treatment. The treatment continued for 14 days. The multiple-patch ground-glass appearance was nearly completely resolved on chest CT (Fig. 1). Cytomegalovirus polymerase chain reaction (CMV PCR) was negative. PCP PCR was positive but PCP stain (Gomori methenamine silver stain) was negative with induced sputum. Bronchoalveloar lavage (BAL) was not performed due to the patient's poor performance status. Human immunodeficiency virus (HIV) antibody testing was negative. Tests for bacteria and fungus were all negative.

The patient (male/58) underwent total gastrectomy with D2 lymph node dissection for gastric cancer in March, 2007. Six cycles of adjuvant chemotherapy including Epirubicin, 5-fluorouracil and cisplatin (ECF regimen) were performed. Antiemetic regimen composed of intravenous dexamethasone 10 mg at days 1, 2, and 3 and serotonin 5-HT3 antagonist at days 1, 2, and 3. During follow up, his cancer recurred. He was treated with palliative chemotherapy with a regimen of mFOLFOX6. After the 12 cycles of chemotherapy were completed, the disease progressed. Second line palliative chemotherapy with a regimen of mFOLFIRI was administered. An antiemetic regimen for both regimens composed of dexamethasone 8 mg at days 1, 2, and 3 and serotonin 5-HT3 receptor antagonist was given. Dyspnea, hypotension and tachycardia without fever occurred 12 days after the 5th cycle of chemotherapy. Chest CT scan showed patchy ground-glass opacifications throughout both lower lobes. PCP was suspected by clinical symptoms and chest CT scan. Empirical treatment with intravenous trimethoprim/sulfamethoxazole and solumedrol was administered to the patient promptly. After 14 days of treatment, his symptoms resolved and the patchy ground-glass opacifications nearly completely disappeared on chest CT scan (Fig. 2). CMV PCR was negative. PCP PCR was positive. HIV antibody test was negative. PCP stain was negative with induced sputum. BAL was not performed due to his dramatic clinical response to anti-PCP therapy.

The patient (male/57) was diagnosed as gastric cancer with liver metastasis in March 2006. He received chemotherapy with TS-1 (oral 5-fluorouracil [5-FU]) plus cisplatin combination regimen. His disease progressed after 4 cycles of TS-1 plus cisplatin chemotherapy. Second line palliative chemotherapy with 5-FU/leucovorin/oxaliplatin (mFOLFOX6) was administered. Progression of his disease was found after 7 cycles of mFOLFOX6 chemotherapy. Docetaxel single was administered to him from February 2007 as a palliative treatment. The antiemetic regimen for TS-1 plus cisplatin was 10 mg intravenous at days 1, 2, and 3, plus serotonin 5-HT3 receptor antagonist from days 1 to 5. Antiemetic regimen for mFOLFOX was the same as for TS-1 plus cisplatin. The pemedication for docetaxel was 8 mg dexamethasone the night before chemotherapy, 10 mg at day 1 and 8 mg bid at days 2 and 3 to prevent hypersensitivity reaction of docetaxel. He was admitted with the chief complaint of dry cough and fever 13 days after the 3rd cycle of docetaxel chemotherapy. Chest CT revealed bilateral multifocal ground-glass opacity with some small cystic change. Empirical treatment with trimethoprim/sulfamethoxazole was started immediately. Anti-PCP therapy was changed to pentamidine due to liver toxicity from trimethoprim/sulfamethoxazole. The change in chest X-ray was shown in Fig. 3. BAL was performed. CMV PCR with BAL fluid was negative. Both PCP PCR and PCP stain with BAL fluid was positive. HIV antibody test was negative.