Lymphatic malformations (LMs) are low-flow vascular malformations which are composed of dilated lymphatic channels, forming septated cyst-like structures (2). LMs are the second most common type of vascular malformation, second to venous malformations (1). The most common locations are in the neck, followed by the axillary region. On MRI, LMs are multiloculated, T2 hyperintense lesions, which may have fluid-fluid levels, and are without flow voids (1, 2). They can involve multiple tissue planes and do not regard anatomical and fascial boundaries (2). Cystic lymphatic malformations are further divided into microcystic, macrocystic, or mixed, based on the size of their cystic components. Macrocystic LMs are composed of larger cysts, while microcystic LMs are composed of smaller cysts and may appear solid on imaging. We present ten cases of microcystic, macrocystic, and mixed lymphatic malformations in a variety of anatomical locations. In addition to demonstrating the imaging findings, we present a review of the literature in regards to each anatomical region. Lymphatic malformations in this presentation include right orbit (n=1), mediastinum (n=2), pulmonary bronchovascular bundles/pleural space (n=1), retroperitoneum (n=1), mesentery (n=2), perirectal and scrotal (n=1), lower extremity (n=2). 6 of these children also had additional sites of T2 hyperintense disease involving the bones or spleen, suggestive of additional lymphangiomas. This presentation summarizes ten cases of lymphatic malformations in a variety of less common anatomical locations and a review of the pertinent literature. <b>References:</b> 1. Flors L, Leiva-Salinas C, Maged IM et al. (2011) MR Imaging of Soft-Tissue Vascular Malformations: Diagnosis, Classification, and Therapy Follow-up. Radiographics 31:1321-1340. 2. White CL, Olivieri B, Restrepo R et al. (2016) Low-flow vascular malformation pitfalls: from clinical examination to practical imaging evaluation- part 1, lymphatic malformation mimickers. AJR 206: 940 – 951. Read More

Meeting name: SPR 2019 Annual Meeting & Postgraduate Course , 2019

Authors: Gaballah Marian, Goldfisher Rachelle

Keywords: Lymphatic malformation, Vascular Malformation

<b>A full-term male was born with a 7 x 7 cm subcutaneous mass with central dark blue discoloration and peripheral erythema on the right flank/buttock. Initial hip and pelvis radiograph at one day old did not show evidence of calcifications. An ultrasound demonstrated an ill-defined, heterogeneous mass with internal vascularity with invasion of underlying muscle. MRI of the abdomen and pelvis with contrast at two days of age showed a T2 hyperintense mass with mild postcontrast enhancement within the right flank with infiltration of the underlying muscles including the right psoas, iliacus, gluteal, and the left erector spinae. The differential diagnosis included: kaposiform hemangioendothelioma, rhabdomyosarcoma (RMS), tufted angioma and neuroblastoma.</b> <b>Given the broad list of differential diagnoses, a core biopsy of the right buttocks was obtained at 6 days of age to further characterize the lesion. Hematoxylin and eosin stained sections demonstrated highly collagenized and sclerotic spindle cells involving the adipose tissues extending into the dermis. Immunohistochemical stained sections showed positivity to desmin, myogenin and MyoD1. Fluorescence in situ hybridization studies indicated the presence of a VGLL2 gene rearrangement. These pathologic findings were consistent with sclerosing spindle cell RMS. At 13 days old, a PET scan showed the right flank lesion with minimal to no FDG uptake, a finding which is consistent with sclerosing RMS given that this sub-type consists mainly of collagen. There were no pulmonary nodules. After multiple chemotherapy cycles, subsequent MRIs of the abdomen and pelvis showed no residual enhancing lesion. The patient will be closely followed for local recurrence.</b> <b>RMS, the most common soft tissue tumor seen in children, are mesenchymal tumors of skeletal muscle and are most often seen in head and neck, but are less commonly noted on the flank. Sclerosing spindle cell RMS is a subtype often seen in childhood, but exceedingly rare in newborns. Cutaneous RMS should be considered in the differential diagnosis of a large subcutaneous lesion in a newborn.</b> Read More

Meeting name: SPR 2020 Annual Meeting & Postgraduate Course , 2020

Authors: Bellew Elizabeth, Sonstegard Anna Marie, Finelt Nika, Goldfisher Rachelle

Keywords: Rhabdomyosarcoma, Sclerosing Spindle Cell Rhabdomyosarcoma, Vascular Malformation