P-159 A sheep in wolf’s clothing – pulmonary tularemia imitates lung cancer

Hintergrund

Francisella tularensis is a bacterial pathogen known to cause tularemia, a rare zoonotic disease transmitted by contact with sick animals, mosquitos, ticks or contaminated water, soil or food. Although starting from a low level, the incidence of tularemia in Germany has been rising during the past ten years. The presentation of tularemia is versatile and depends on the pathogenic entry route. Glandular, ulceroglandular, intestinal and pulmonary forms belong to the most common clinical manifestations.

Material und Methode

We present a clinical case of pulmonary tularemia treated in our center.

Ergebnis

An 82-year-old, male patient was referred to our center for further evaluation of a lung mass. He first presented at a community hospital with orthostatic dysregulation, increasing weakness, a low-grade fever and elevated inflammatory parameters. Initial CT scan revealed an abnormal lesion in the right upper lobe as well as hilar and mediastinal lymphadenopathy. [¹⁸F]-FDG-PET/CT scan showed a spiculated, hypermetabolic 49x39x33mm mass highly suspicious of malignancy and multiple unilateral, enlarged lymph nodes with increased glucose consumption. Endobronchial ultrasound-guided and CT scan-guided transthoracic biopsies produced inconclusive results. After discussion in our interdisciplinary tumor conference, surgical intervention was recommended to remove and classify the lesion. Intraoperatively, the tumor occupied large parts of the upper lobe and appeared to infiltrate the lower lobe. Upper lobectomy, wedge resection of the lower lobe and radical lymphadenectomy were performed. Unexpectedly, histopathological examination of the resected parts failed to detect malignant cells. The resected mass and lymph nodes contained foci of necrosis and granulomatous inflammation, indicative of an infectious etiology. An extensive work-up for infectious diseases provided serological evidence of antibodies against F. tularensis. RT-PCR and fluorescence in situ hybridization performed on resected lung tissue confirmed the serological findings and proved the presence of F. tularensis subsp. Holarctica. The patient was treated with ciprofloxacin for 14 days and quickly recovered. Patient history did not reveal any contact with wild animals or hunting activities except for spending time in nature.

Schlussfolgerung

Pulmonary tularemia is a rare but important differential diagnosis that may be considered in patients presenting with unspecified lung masses suspicious of malignancy.

Publication History

Article published online:
06 September 2021