An unusual endobronchial lesion: expanding the differential diagnosis

Identification of CT Features to Differentiate Pulmonary Sarcoma from Carcinoma

Background  Primary lung sarcoma (PLS) differs in management protocols and prognosis from the more common primary lung carcinoma (PLC). It becomes imperative to raise a high index of suspicion on radiological and pathological features. Purpose  The aim of this study is to highlight the variable imaging appearances of PLS compared with PLC, which impacts radiologic - pathologic correlation. Materials and Methods  A retrospective observational study of 68 patients with biopsy-proven lung tumors who underwent baseline imaging at our tertiary care cancer hospital was conducted between January 2018 and March 2022. The patient details and imaging parameters of the mass on contrast-enhanced computed tomography (CECT) were recorded and analyzed for patients with PLS and compared with PLC. Follow-up imaging was available in 9/12 PLS and 52/56 PLC patients. Results  Among 12 patients with PLS, 5 patients had synovial sarcoma on histopathology. PLS was seen in patients with a mean age of 40.8 years; the mass showed a mean size of 13.2 cm, lower lobe (75%), parahilar (75%), hilar involvement (41.7%), oval shape (41.7%), circumscribed (25%) or lobulated (75%) margins, lower mean postcontrast attenuation of 57.3 HU, fissural extension (50%), calcification (50%), and no organ metastasis other than to the lung. PLC (56 patients) was seen in the elderly with a mean age of 54.8 years; the mass showed a mean size of 5.7 cm, irregular shape (83.9%), spiculated margins (73.2%), higher mean postcontrast attenuation (77.3 HU), chest wall infiltration (30.4%), and distant metastasis (58.9%) at baseline imaging. A statistically significant difference ( p  < 0.05) was seen between sarcoma and carcinoma in the mean age, size, site, shape, margins, postcontrast attenuation, presence of calcifications, fissural extension, and distant metastasis. Conclusion  The distinct imaging features of sarcoma help in differentiating it from carcinoma. This can also be used to corroborate with histopathology to achieve concordance and guide clinicians on further approach.

Endobronchial Obstruction: A Case of Well-Differentiated Liposarcoma

Atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) is a rare subtype of endobronchial tumor that has been rarely reported in medical literature. Due to its low incidence, distinguishing it from endobronchial lipoma poses a significant diagnostic challenge, necessitating histopathologic and cytogenetic analysis. As of today, the treatment and surveillance protocols for these neoplasms remain poorly defined, often resulting in their misclassification and treatment as endobronchial lipomas. We present a case involving a 72-year-old male who presented with worsening dyspnea and cough. Diagnostic imaging revealed an endobronchial lesion obstructing the left main bronchus. The patient underwent a flexible bronchoscopy that identified a polypoid mass causing significant obstruction, which was subsequently resected via cryoablation. Histopathology confirmed ALT/WDL, supported by genetic analysis revealing chromosomal alterations. Following the intervention, symptoms resolved, with no recurrence on follow-up imaging. Differentiating ALT/WDL from endobronchial lipomas is necessary not only because it influences treatment decisions but also because it can significantly affect the prognosis of patients diagnosed with ALT/WDL. In this case, we emphasize the importance of considering ALT/WDL in the differential diagnosis of endobronchial tumors and highlight the use of flexible bronchoscopy as a viable substitute for rigid bronchoscopy, serving not only as a diagnostic tool but also as a therapeutic method.