Primary pulmonary amebic abscess in a patient with pulmonary adenocarcinoma: a case report

Abstract

Background: Primary pulmonary amoeba is very rare and here we report a case of a 68-year-old man presenting with primary pulmonary amoeba after undergoing chemotherapy for lung adenocarcinoma.

Case presentation: In October 2016, the man aged 68 was admitted to our hospital because of repeated cough for 8 months and hemoptysis for 1 month. He was diagnosed lung adenocarcinoma and underwent surgery in 2012 without receiving chemotherapy. In March 2016, the patients suffered recurrence of cancer and was treated with chemotherapy. After 2 months of chemotherapy, the patient had consistent cough with white sputum, and chest CT showed a local lung nodule. The physicians suspected that the patient had pulmonary infectious diseases, and he was treated with empirical antibacterial treatment. However, his symptom wasn't relieved and later the percutaneous lung biopsy found trophozites of Entamoeba histolytica. After administration of metronidazole, the symptoms of the patient were markedly relieved and the lesions were absorbed.

Conclusions: In such cases where patients with pulmonary nodules were in immunodeficiency state and had adequate but ineffective anti-bacterial treatment, Entamoeba histolytica infection could be one of the rare causes. Percutaneous lung biopsy should be recommended and specific dying for parasites should be done when necessary.

Keywords: Amebiasis; Pulmonary adenocarcinoma; Pulmonary amebic abscess.

Fig. 1

Pulmonary CT scan revealing multiple nodules in bilateral lung, including right upper lobe (a and b) and right middle lobe (c), which proved recurrence of lung cancer later by biopsy. (2016-3-21)

Fig. 2

The patient’s pulmonary CT scan showed changes of the lesion during course of disease. a Right upper lobe nodule revealing recurrence of lung cancer confirmed by pathology (2016-3-21); b Right lung lesion became larger accompanied by an empty cavity after chemotherapy (2016-5-4); c No significant change of the right lung lesion after levofloxacin and cefepime treatment (2016-5-18); d No significant change of the right lung lesion after praziquantel treatment (2016-9-5); e Absorbed lesions after metronidazole treatment (2016-12-26); f No recurrence of amoeba during 6-month follow-up (2017-06-06)

Fig. 3

Pathological examination of the lung revealed trophozoites of Entamoeba histolytica. a, b Haematoxylin Eosin (HE) stain; c, d Periodic acid–Schiff (PAS) stain; arrows refer to the amoebic trophozoites)

Fig. 4

The timeline of the patient’s medical history, diagnostic workup and treatments