QUIZ: No. 11, 29/03/2026

Diagnosis: Rectal neuroendocrine tumor with hepatic metastases (mulberry appearance)

Findings: CECT abdomen demonstrates hepatomegaly with extensive bilobar involvement by multiple, variably sized hypodense lesions. These lesions are closely packed and show a tendency to coalesce, forming large lobulated masses with irregular, bosselated margins. Individual lesions demonstrate central low attenuation suggestive of necrosis with relatively denser peripheral viable tumor, producing a characteristic clustered or “mulberry-like” appearance. No true cystic features or daughter cysts are identified. An associated rectal mass is noted, which appears bulky with transmural/exophytic component rather than a purely submucosal lesion, suggesting an aggressive primary tumor.

Discussion

Ø  The “mulberry appearance” of liver metastases refers to multiple coalescent metastatic nodules with central necrosis and peripheral viable tumor, giving a lobulated clustered morphology. This pattern is classically associated with hypervascular metastases, most commonly from neuroendocrine tumors (NETs).

Ø  Neuroendocrine tumors frequently metastasize to the liver via hematogenous spread, often resulting in multiple bilobar lesions. These metastases are typically hypervascular and may undergo central necrosis as they enlarge, producing the characteristic appearance seen in this case.

Ø  This clustered coalescent morphology has been described in hypervascular metastases, particularly neuroendocrine tumors, due to rapid growth and necrosis

Ø  Diagnosis can be confirmed with serum markers (Chromogranin A, 5-HIAA) and functional imaging such as Ga-68 DOTATATE PET.

Teaching pearl:

Multiple coalescing necrotic liver metastases producing a “mulberry appearance” are highly suggestive of neuroendocrine tumor metastases rather than adenocarcinoma.