Histopathology:
- Submucosal pink thick areas with almost unremarkable overlying squamous epithelium on low power view.
- Nodular mass (red arrow) composed of intersecting fascicles of bland spindle cells with some degree of degenerative nuclear changes and abundant pink cytoplasm. The Blue arrow point outs the hyaline globules in the smooth muscle cells
- Mitotic figures are almost not seen. Necrosis is also not seen.
Practical points of Pathoclinics:
- In any esophageal spindle cell mass lesion, leiomyoma is the first consideration, as it is the most common benign tumor of the esophagus.
- Most esophageal leiomyomas present as a single circumscribed nodular submucosal/intramural mass lesion in the distal esophagus (size: 1-5 cm) in adults, but multiple masses can be seen in approximately one-fourth of cases. Multiple leiomyomas are small (minute 1 – 2 mm; seedling leiomyomata) and common around the gastroesophageal junction. The cut surface of leiomyomas show pinkish-gray to white with a whorled pattern. The overlying mucosa appears normal except rarely ulcerated in the large tumor. Occasional leiomyoma can show calcification.
- Esophageal leiomyomas are very rare in children.
- Clinically large bulging mass may produce obstructive symptoms. Polypoid presentation is uncommon. Clinically esophageal leiomyomas may simulate carcinoma or gastrointestinal stromal tumor.
- Esophageal leiomyomas most commonly arise in the inner circular muscle layer, followed by the muscularis mucosae. The outer longitudinal muscle layer is an uncommon location. In the present case, leiomyoma looks to arise from muscularis mucosae.
- In a few cases of diffuse leiomyomatosis affecting gastroesophageal junction, extensive hypertrophic thickening of the esophageal wall, particularly inner circular muscle layer of the muscularis propria, has been noted, that give rise to symptoms similar to achalasia. It is likely that both idiopathic muscular hypertrophy of the esophageal wall and diffuse leiomyomatosis are related conditions. Histologically, diffuse leiomyomatosis is characterized by nodular interlacing pattern of muscle fibers, which are not seen in the diffuse hypertrophy of the muscular wall.
- An uncommon association of Alport syndrome (hereditary hematuric nephropathy, sensorineural deafness, and ocular impairment) and esopahgeal leiomyomatosis has been found.
- Careful attention to mitotic count and necrosis is necessary to distinguish between benign and malignant smooth muscle tumors.
- Associated overlying squamous dysplasia or carcinoma can be seen along with underlying leiomyoma.
- Leiomyomas are positive for desmin, alpha-smooth muscle action, and h-caldesmon. It is negative for CD34, CD117, DOG1, and S100. Later markers help to distinguish it from GIST and schwannoma.
- Endoscopic excision of small tumors and esophagectomy for large tumors are required.
Reference:
Delteil C, Macagno N, Daniel L, D’Journo XB, Guisiano S, Garcia S, Secq V. Léiomyomatose œsophagienne diffuse et syndrome d’Alport : rapport d’un cas [Diffuse esophageal leiomyomatosis and Alport’s syndrome: A case report and review of the literature]. Ann Pathol. 2019 Feb;39(1):36-39. French. doi: 10.1016/j.annpat.2018.08.007. Epub 2018 Oct 12. PMID: 30322718