Diagnostic conundrum in a patient with small cell lung cancer (SCLC)

ABSTRACT

Introduction: It is rare for pulmonary SCLC to present as a cavitating lesion unlike non-small-cell-cancer (NSCLC). Hence, if a cavitating lesion is found with histo-pathology showing SCLC, it is important to rule out alternate diagnosis e.g., infection [1]. Case We present the case of a 41-year-old-male of Bangladeshorigin. He was referred on 2ww-pathway to UHL Glenfield hospital lung cancer team for haemoptysis. Clinical assessment (05/12/2019) revealed that he had 4kg weight loss/haemoptysis/anorexia/fatigue. He was a current smoker (10 pack-years) with no significant past/ family history. He worked in a restaurant. Clinical examination was unremarkable. Chest x-ray showed left-hilar-mass. CT scan revealed 3.2cm mass with peripheral cavitation and mild focal enhancement without calcification/mediastinal-lymphadenopathy. Differentials included cancer/rheumatoid arthritis/infection. Bloods including ANCA/ANA/rheumatoid factor and bronchial-washings microbiology/cytology were unremarkable. He was given antibiotics. He did not attend subsequent 2 out-patient-appointments. Repeat CT scan (March 2020) showed growing lesion with focally dilated vessel. CT-guided biopsy was advised but he declined it due to COVID19 pandemic. In May 2020, he agreed to undergo CT-guided biopsy. However, pre-procedure CT scan showed possible pseudoaneurysm. CT-guided biopsy was deemed high-risk and not attempted. Lung cancer MDT advised lobectomy given diagnostic dilemma. Patient declined surgery. CT in November 2020 showed progressive lesion. Patient still was not keen for surgery. He was admitted in June 2021 with haemoptysis. CT scan showed progressive cavitating disease with necrotic left hilar/mediastinal lymph nodes. He underwent EBUS-TBNA that confirmed SCLC. Given cavitating lesion and long history, left lower lobe lesion was deemed unlikely to be due to SCLC. He was referred to infectious disease (ID) clinic. Blood parasitology screen revealed positive Hydatid ELISA. He did not attend subsequent outpatient appointments in Oncology/ID clinics and has been discharged. Learning points There were two pathologies hydatid cyst (Fig. 1a);SCLC developed between November 2020 and June 2021 (Fig. 1b). 1) To look for cause of a cavitating lesion even if SCLC is diagnosed. 2) To consider hydatidcyst in lung-cavity differentials.(Figure Presented) Fig. 1