Primary Pulmonary Large Cell Carcinoma with Syncytiotrophoblastic Aspect: Report of a Case

BACKGROUND: To present the case of a primary large cell lung carcinoma with syncytiotrophoblastic aspect. METHODS: A 54-year-old smoking man (60 pack/years), with no significant past medical history, presented for incidental radiological finding of a 5cm mass in the right middle lobe with partial invasion of the lower lobe (Fig.1). A PET/CT-scan showed a unique intense FDG-uptake of the pulmonary mass. A trans-thoracic fine-needle aspiration led to the diagnosis of non-small-cell lung cancer with sarcomatoid features. Preoperative cardiac and pulmonary function tests were normal. RESULTS: The patient underwent a right middle lobectomy and wedge resection of the lower lobe and radical lymphadenectomy through a posterolateral thoracotomy. The postoperative course was uneventful; the patient was discharged on the seventh postoperative day. After 52 months the patient is alive and disease-free. Macroscopically, the mass measured 5.5cm, had a greyish colour with lobulated margins. Microscopically, a poor differentiated tumor characterized by giant and medium pleomorphic cells sometimes with syncytial-trophoblastic features were observed (Fig.2a). Immunohistochemically, tumor cells were positive for beta-human-chorionic-gonadotrophin (Beta-HCG) (Fig.2b), anti-endomisium antibody (EMA), placental alkaline phosphatase (PLAP) e cytokeratin 7 (CK 7); the cells resulted negative for octamer-binding transcription factor-4 (OCT-4) (Fig.2c), spalt like transcription factor 4 (SALL4) (Fig.2d) and glypican-3. A subsequent genital examination and testicular ultrasonography excluded the presence of a primary gonadal choriocarcinoma. Beta-HCG serum levels were undetectable after surgery. Based on the above findings, a diagnosis of primary large cell lung carcinoma with syncytiotrophoblastic aspect was made. Final pathological stage was pT2aN0M0. No adjuvant therapy was proposed. CONCLUSION: Large cell lung carcinoma with syncytiotrophoblastic aspect is an extremely rare finding. The prognosis is usually poor irrespective of the treatment; a few long-term survivors have been reported.