Benign metastasizing fumarate hydratase (FH)-deficient uterine leiomyomas: clinicopathological and molecular study with first documentation of multi-organ metastases.

Leiomyoma is the most prevalent benign tumor of the female reproductive system. Benign metastasizing leiomyoma (BML) is a rare phenomenon that presents at distant sites, typically the lungs, exhibiting histopathological features similar to the primary uterine tumor in the absence of malignancy features in both. Fumarate hydratase-deficient uterine leiomyoma (FH-d UL) is an uncommon subtype among uterine smooth muscle tumors (0.5-2%), showing distinctive histomorphology and FH inactivation. The majority of FH-d ULs are sporadic, caused by somatic FH inactivation, while a minority of cases occur in the context of the hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome caused by germline FH inactivation. Metastasizing FH-d UL has not been well documented and might be under-reported. Here, we present two cases (21- and 34-year-old females) who presented with metastasizing FH-d UL after myomectomy/hysterectomy with histologically proven multiple lung metastases in both, in addition to multi-organ involvement in one case (cervical-thoracic lymph nodes, left kidney, perihepatic region, left zygomatic bone, and soft tissues). Pathological examination confirmed FH-d leiomyomas in the primary/recurrent uterine tumors, multiple lung lesions, and a renal mass. The minimal criteria for diagnosis of leiomyosarcoma were not fulfilled. Genetic testing revealed germline pathogenic FH variants in both cases (c.1256C > T; p.Ser419Leu in Case 1 and c.425A > G; p.Gln142Arg in Case 2). These novel cases highlight a rare but possibly under-recognized presentation of FH-d BML. Our study suggests that FH-d BML cases might be enriched for the HLRCC syndrome.

Right Ventricular Outflow Tract Intimal Sarcoma Extending into the Main Pulmonary Artery: A Case Report.

Intimal sarcomas are rare malignant mesenchymal tumors that arise in the large arteries and rarely in the heart. Herein, we report the case of a 55-year-old man who was referred for further assessment of a right ventricular outflow tract mass. Assessment with cardiac magnetic resonance imaging revealed an enhancing mobile mass arising within the right ventricular outflow tract and extending into the main pulmonary artery. The initial diagnostic possibilities included thrombus and myxoma. The patient underwent surgical recession of the mass and the histopathology examination confirmed the diagnosis of cardiac intimal sarcoma.

Imaging features of Lipoblastoma.

Lipoblastoma is a rare benign soft tissue tumor found in infants and young children. It presents as an enlarging mass commonly observed in extremities, trunk, head and neck regions. Imaging features include a hyper-echoic mass on ultrasound, heterogonous fat density lesion on CT scan with enhancing septations and no calcification, and high T1 signal mass that drops the signal intensity on fat suppression MRI images. Total excision of such lesion is the treatment of choice, and follow-up is recommended to rule out recurrence.

Renal Epithelioid Angiomyolipoma: A Case Report and Review of Literature.

Epithelioid angiomyolipoma (EAML) is an uncommon renal neoplasm with malignant potential. It is classified under the group of perivascular epithelioid cell tumors and can be sporadic or as part of the tuberous sclerosis complex. On imaging, unlike classical AML that contains fat, EAML has a very low percentage of fat which can mimic the imaging findings of renal cell carcinoma. We reported a 31-year-old female who had a history of renal failure and bilateral renal masses. Magnetic resonance imaging of the abdomen revealed bilateral large renal masses replacing renal parenchyma with features suggestive of bilateral renal AML. The patient underwent left nephrectomy, and histopathology examination findings were consistent with the diagnosis of EAML.