- Variable size irregular, haphazardly arranged glands look like an infiltrative pattern, in the wall of fallopian tube, around the central lumen.
- Some of these glands do not communicate directly with the central lumen, while few communicate with the main lumen (blue arrow).
- Some glands are small and tubular, while others are large and cystically dilated with an irregular contour. There are no evidence of stromal cells around glands. These glands are lined by a single layer of ciliated tubal epithelium without atypia.
- Elongated irregular dilated glands reach up to the hypertrophic and disorganized muscular wall of the fallopian tube.
- Focal area of the fallopian tube folds/plica show calcified debris and a few psammomatous like calcification.
- There is no stromal reaction/desmoplasia, cytologic atypia, or mitoses.
Practical points of Pathoclinics:
- Salpingitis isthmica nodosa is a diverticulum of fallopian tube, in the isthmus portion, imparting a false infiltrative appearance on low magnification. On histopathology, some glands communicate with the central lumen, indicating the diverticular process.
- The possible etiologies are inflammatory and adenomyosis-like processes.
- Salpingitis isthmica nodosa is usually asymptomatic and incidental findings.
- It is often bilateral and important cause for infertility and ectopic pregnancy.
- Gross appearance of one or more yellow-white firm smooth nodules in the isthmus portion of the fallopian tube, ranging in 1–2 cm in diameter.
- Salpingitis isthmica nodosa is frequently associated with chronic salpingitis.
- In some cases, the presence of endometrioid stromal cells around glands creates hurdles to differentiating it from tubal endometriosis. However, stromal cells are usually scanty or absent.
- An uncommon complication is the rupture of a large size deep diverticular nodule with intra-abdominal bleeding and pelvic pain.
- Look for cytologic atypia and stromal desmoplasia to rule out the neoplastic lesion.