Low-grade appendiceal mucinous neoplasm (LAMN)

Case contributed by Keshaw Kumar
Diagnosis certain

Presentation

Right iliac fossa pain, fever, and vomiting. Increased urinary frequency.

Patient Data

Age: 45 years
Gender: Female

Abdomen

ultrasound

Well-defined lobulated heterogeneously hypoechoic area of size ~ 5.5 x 2.6 × 3.8 mm (Vol. ~ 28 cc) in the right iliac fossa region with mild surrounding inflammatory changes and no internal vascularity. It seems to be communicated with the base of the appendix. The rest of the appendix could not be separately visualized. The ileocecal junction appears normal. The small echogenic focus of size ~6.2 mm is seen in this area. ? Appendicolith. An appendicular abscess was the likely possibility. Other possibilities include appendicular mucocele with superimposed infection.

Grade I fatty liver.

Approx 2.5 x 2.3 cm sized ill-defined hetero-echoic lesion in the lower uterine segment/cervix on the right side. ? Fibroid.

Insignificant post-void residual urine.

CECT abdomen and pelvis

ct

Peripherally enhancing lesion of size ~ 5.7 × 3.4 x 3.0 cm in the right iliac fossa region, originating from the tip of the cecum. The appendix is not separately visualized from the lesion. Moderate surrounding inflammatory changes were seen. The ileocecal junction appears normal. An appendicular abscess is a likely possibility. Other possibility includes appendiceal mucocele with superimposed infection.

Approx. ~ 2.3 × 2.4 cm size peripherally enhancing hypodense lesion in the lower uterine segment/cervix on the right side. ? Fibroid.

The appendicular lump was present stuck to the anterior abdominal wall in the suprapubic region. It was noted that the engorged base of the chronically inflamed appendix with an antibioma-like appearance was extending well into the cecum and it was not feasible to perform an appendectomy alone. It was therefore planned to do an ileocecal resection.

Histopathological report

Photo

Histopathology result.

Case Discussion

The above case of low-grade appendiceal mucinous neoplasm closely mimics the appendicular abscess clinically and imaging-wise.

Co-author: Dr Sanjoy Kumar (Director, GI Surgery).

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