Disseminated Peritoneal Leiomyomatosis: Description of a Case, Radiologic Semiotics and Differential Diagnosis

Leiomyomatosis peritonealis disseminata or disseminated peritoneal leiomyomatosis (DPL), is a rare nosological entity characterized by multiple leiomyomas growing within the abdominal region. It is one of the uncommon manifestations of extra-uterine leiomyomas and an eventuality that can lead to diagnostic difficulties, especially in neoplastic patients. This pictorial review aims to illustrate the multimodal characteristics of DPL, providing at the same time relevant information regarding pathogenesis, clinical presentation, and treatment. Furthermore, as DPL may enter in differential diagnosis with other atypical smooth muscle tumour localization or abdominal malignancies, such as retroperitoneal leiomyosarcoma or peritoneal carcinomatosis, the review provides a concise description of each condition: the main epidemiological and pathogenetic aspects are summarized, along with essential information on clinical presentation and radiological imaging, closing with some notes on possible treatment options.

A case of incidental detection of DPL in a patient undergoing staging of breast cancer is employed as an example to illustrate the diagnostic difficulties that may be encountered in such scenarios: the finding of multiple vascularized nodules in the abdomen aroused the suspicion of carcinomatous localizations, and the patient underwent in-depth investigations with multiple imaging techniques by ultrasound, computed tomography and magnetic resonance.

Using imaging methods with better contrast resolution in the definition of soft tissues made it possible to orient the diagnostic suspicion over DPL, subsequently confirmed by histological evaluation after laparoscopic excision of bigger nodules. Once the possibility of peritoneal localization of breast cancer was excluded, the patient was treated with neoadjuvant therapy, surgery and adjuvant therapy. Follow-up imaging showed no signs of breast cancer recurrence nor significant changes in the remaining DPL nodules.

Knowledge of the atypical presentation patterns of leiomyomas, the related imaging characteristics and the differential diagnosis allows both the clinician and the radiologist to formulate more accurate diagnostic hypotheses, thus ensuring better patient management from the view of the subsequent possible invasive diagnostic and therapeutic options.