Patient Data
Multiple foci of centrilobular emphysema are identified in the lungs with slight predominant in the bilateral upper lobes. Scarring/atelectasis are identified in the bilateral lung bases. A small pleural calcification is identified in the posterior aspect of the right 8th intercostal space. The lungs and pleura are otherwise clear.
No enlarged lymph nodes are demonstrated in the mediastinal, hilar or axillary regions.
A 24 x 19 x 25 mm exophytic low-density mass with a thin medial rim of calcification is identified in the left lateral aspect of the distal esophagus, approximately 5 cm from the gastro-esophageal junction. It is of the smooth border without invasion to the adjacent left atrium and descending aorta.
The imaged upper abdomen is normal. No evidence of suspicious bony erosion.
Well-defined hypodense exophytic mass with likely central necrosis and rim of calcification.
The patient went for gastroscopy and biopsy:
Microscopy: The specimen consists mainly of blood and fibrin, along with admixed fragments of the tumor. The tumor is composed of a haphazard arrangement of spindle cells that have fairly uniform elongated nuclei with blunt ends, and eosinophilic cytoplasm. The stroma shows myxoid alteration with focal hyalinosis. Immunoperoxidase stains have been performed and the spindle cell population shows strong positive staining for CD117 (cKit) and does not stain with desmin, SMA or S-100. Only a scant amount of tumor remains in the block.
Although only a scant amount of the tumor is present, and this has a non-specific morphology, the immunoprofile (CD117+ / desmin-) favors a GIST.
Conclusion: Esophageal lesion, biopsy: Spindle cell tumor, features favoring a gastrointestinal stromal tumor (GIST).
Case Discussion
This case shows an incidental exophytic mass in the distal esophagus. The differential on imaging includes leiomyoma, favored as it is the most common being tumor od the esophagus and given the calcifications, and GIST. Gastroscopy biopsies favored GIST due to the positive staining for CD117 (c-KIT).