Mesenchymal Hamartoma of the Liver and Spleen-A Rare Pseudotumour in Adults

Abstract

Hepatic mesenchymal hamartoma is the third most common liver neoplasm of the pediatric age group, rarely diagnosed in adults, with under 50 cases having been reported so far. Mesenchymal hamartoma of the spleen is a very rare vascular lesion, documented in less than 200 cases since 1861 when it was first described by Karl von Rokitansky. 1.1. Aim: The aim of this paper is to discuss the differential diagnosis of these tumour-like lesions and the association between them, especially considering their rarity. 1.2. Methods: We present a case of multifocal mesenchymal hamartoma of the liver and spleen in a 51-year-old female patient. The hepatic tumour appears as a macro nodular lesion involving the interface between segments V and VIII [30x28mm], showing central scarring upon MRI imaging and suggesting the diagnosis of focal nodular hyperplasia. Moreover, a sub capsular splenic cystic mass was also revealed, involving the sub diaphragmatic surface of the organ [15x10mm]. 1.3. Results: The histological examination of the hepatic tumour revealed a myxoid stromal proliferation, composed of stellate and fibroblastoid cells, bile ducts with inconspicuous lumina, small vascular structures and chronic non-specific inflammatory infiltrate. On microscopic examination, the splenic lesion exhibited nodular collagenous fibrosis, radial septa and large hyalinized areas. 1.4. Conclusion: A key aspect in the effective treatment of patients diagnosed with mesenchymal hamartomas is surgery with negative margins. The peculiarity of this case consisted of the incidental finding of multiple liver tumours, the incidental finding of the splenic mass, and the rarity of this particular association in adults.