Lee Sean,  Shah Amisha

Final Pr. ID: Poster #: CR-036

Rubinstein-Taybi Syndrome (RTS) and infantile myofibromatosis (IM) are both rare genetic disorders. RTS is marked by craniofacial dysmorphism, short stature, and skeletal abnormalities, while IM usually appears as one or more soft tissue nodules, which can affect bones and visceral organs. We present the rare case of a male newborn diagnosed with both RTS and IM. At birth, the patient showed unusual facial features, small size, and polydactyly. The initial skeletal survey showed multiple lucent lesions in the metaphyseal long bones. A follow-up skeletal survey at four months showed growing lucent lesions, though they had developed benign features of a sclerotic rim and a narrow zone of transition. New bone lesions were seen in the flat bones and spine with vertebra plana deformity. Additionally, calcified soft tissue masses were found. Further characterization by MRI suggested marrow infiltration of the lesions. Due to the higher cancer risk in RTS patients, leukemia, lymphoma, or metastatic neuroblastoma were the main concerns, while Langerhans cell histiocytosis was considered less likely due to the metaphyseal pattern. A bone biopsy at two sites confirmed multicentric myofibroma, consistent with IM. Genetic testing found a PDGFRB mutation linked to IM. The patient’s mother tested positive for the same mutation and recalled skin involvement as an infant. The patient tested positive for a de novo CREBBP mutation linked to RTS. These findings suggested autosomal dominant inheritance of IM, while RTS arose sporadically. A whole-body MRI ruled out visceral involvement, a good prognostic factor for IM. The patient received chemotherapy and responded well until it was stopped due to adverse effects. At age 8, he had surgery for a tethered cord, a known complication of RTS. Shortly after, a new lucent lesion, likely a recurrent myofibroma in the right femoral neck, was incidentally found on an abdominal X-ray obtained for pain. The patient is currently under clinical and imaging surveillance. No reported case has yet shown the coexistence of RTS and IM, and there is no known link between the two. This case highlights the importance of considering IM and other rare conditions in the differential diagnosis of multiple lucent bone lesions. A coexisting syndrome can complicate the picture and delay diagnosis. Imaging, biopsy, and genetic testing were key in diagnosing and managing this case. Read More

Authors:  Lee Sean , Shah Amisha

Keywords:  Bone Tumor, Rubenstein-Taybi Syndrome, Infantile Myofibromatosis

Prince Morgan,  Edwards Emily

Final Pr. ID: Poster #: CR-010

Infantile myofibromatosis (IM) is a rare congenital disease of early childhood. Approximately 50% of cases are diagnosed prenatally, and 90% are diagnosed prior to 2 years of age. Solitary IM, multicentric IM without visceral involvement, and generalized IM with cutaneous and visceral involvement have been described, with generalized IM carrying a poor prognosis and high mortality rate. The following reported case demonstrates an unusually high disease burden.
The patient was a monochorionic diamniotic twin fetus found to have a cystic and solid left facial mass on routine prenatal anatomy scan. Initial differential included congenital hemangioma, as well as lymphatic malformation and teratoma. Multiple prenatal ultrasounds and fetal MRI were obtained between gestational age 22w0d and delivery. At 32w2d, a new large paraspinal mass extending from the thoracic spine to the proximal right lower extremity was noted. During retrospective review, mild soft tissue thickening was noted in this region on fetal MRI. At this point, a vascular malformation was favored, with a differential of congenital rhabdomyosarcoma less likely. Ultrasound surveillance for the remainder of the pregnancy showed enlargement of the paraspinal mass with extension into the right retroperitoneal space.
The patient was delivered at 35w0d gestation via cesarean-section. On physical examination, she was found to have multiple masses involving the face, and the paraspinal, buttock, and bilateral lower extremity soft tissues. While atrophic papules were present, there were no overlying skin changes as would be expected with vascular malformations. Given the firmness of the masses and atrophic papules, the diagnosis of infantile myofibromatosis was suspected.
Whole-body MRI with contrast was obtained, demonstrating extensive heterogeneously enhancing soft tissue masses involving the left check, lower back extending into the retroperitoneal space, bilateral gluteal muscle and lower extremities.
The patient’s clinical status declined, and given the poor prognosis, was transitioned to comfort care and expired at age 2 months. Post-mortem autopsy confirmed the diagnosis of generalized infantile myofibromatosis with innumerable myofibromas of the right atrium, ventricles, intercostal muscle, diaphragm, thyroid, lungs, pancreas, adrenal glands, vertebrae, and paraspinal muscles.
The surviving twin is currently 2 years of age and is screened with whole-body MRI annually without evidence of disease. Read More

Authors:  Prince Morgan , Edwards Emily

Keywords:  Infantile Myofibromatosis, Fetal Imaging, Congenital

Evens Ashley,  Gonzalez-gomez Ignacio,  Neville Kucera Jennifer

Final Pr. ID: Poster #: CR-002

Infantile myofibromatosis is a rare condition consisting of benign fibrous tumors typically deposited in the skin, soft tissues, muscles, bones, and visceral organs. The entity can be solitary or multicentric. Although controversial, outcomes are generally worse in cases with visceral organ involvement. The prognosis is generally favorable in cases that lack visceral organ involvement, with a majority of cases showing spontaneous regression.

The imaging findings of infantile myofibromatosis will be illustrated using both prenatal and postnatal imaging including ultrasound, MRI, radiography, CT, and bone scintigraphy. We also present gross specimen and pathology images.

Our case involves a 33 week 4 day gestational age male fetus that initially revealed dilated loops of bowel on ultrasound. Fetal MRI was performed at 34 weeks and 4 days, which demonstrated the dilated loop was colon in the region of the hepatic flexure. Additionally, multiple solid-appearing lung masses were noted, which had not been visualized on ultrasound. Because of concern for a possible metastatic process, the entire fetus was thoroughly imaged, but no primary source was found. The differential diagnosis that was given on the fetal MRI included metastatic disease from the mother or fetus, infantile myofibromatosis, or infectious etiology.

The mother underwent induction of labor at 35 weeks 4 days, and the baby was born via uncomplicated vaginal delivery. To exclude transplacental metastases, the mother underwent dermatologic skin check, mammography, colonoscopy, and head CT, all of which were negative.

Postnatal radiographs of the baby revealed a focally dilated loop of bowel, and the patient underwent exploratory laparotomy. In the OR, nodules were noted on the small bowel serosa resulting in a bowel obstruction. Chest radiograph and CT also confirmed the presence of multiple solid lung masses. Bone scintigraphy was negative. Pathology from one of the bowel nodules revealed infantile myofibroma. Our patient has not undergone any therapeutic treatment, and follow up imaging has demonstrated continued spontaneous regression of the lung masses.

Although infantile myofibromatosis is a rare entity, it is important to include in the differential diagnosis in a fetus with multiple solid-appearing lung masses. Throughout the clinical course of these patients, imaging plays an imperative role in the assessment of these lesions.
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Authors:  Evens Ashley , Gonzalez-gomez Ignacio , Neville Kucera Jennifer

Keywords:  infantile myofibromatosis