Abdominal Wall Mass: Myofibroma

This is a case involving a 12-year-old patient with a history of abdominal wall masses, which were initially diagnosed as benign but required further assessment. Questions were raised about the management of the patient's condition, the need for genetic screening, and the appropriate surveillance for this patient. Additionally discussed were the complexities of genetic testing, the pathology of myofibromas, and a case of a child with a large cheek biopsy that resolved spontaneously.

Next steps

• Patient referred to oncology and genetics for comprehensive surveillance and follow-up.

• Specialized follow-up with hematology oncologist to discuss familial cancer syndrome.

• Medical team to consider full body MRI for the patient to screen for potential smaller lesions, including those in bone.

Summary

Myofibroma Case Discussion and Imaging Findings

This case involved a 12-year-old male patient, who had a history of abdominal wall masses. The patient had a previous condition since birth, where he had small masses over the right mandibular joint. An ultrasound and MRI showed that the mass was arising from the interior lateral aspect of the parasitic land. An incisional biopsy in 2023 revealed myofibroma. The patient's family history was significant, with his sister and father having similar conditions. Genetic analysis revealed a heterogeneous variant. An ultrasound done in September 2023 and repeated in February 2024 showed a well-defined oval lesion within the deep subcutaneous soft tissues of the left lower anterior abdominal wall. The lesion was stable in appearance and size over 5 mo. Underlying muscle and overlying soft tissues were unremarkable. The lesion showed some internal Doppler flow on ultrasound. The imaging suggested that the lesion was not aggressive.

Patient Case Management and Follow-Up Discussion

Moderators expressed curiosity about the management rationale for a patient's case, which was initially observed as benign but later required further assessment. The patient was lost to follow-up for 5 mo before being reassessed. Moderators also asked about the trajectory of the patient's condition, specifically in relation to certain characteristics.

Large Mass in Infant: Surgical Approach and Surveillance

They discussed the case of a large mass in an infant that was biopsied and diagnosed. Such masses can resolve spontaneously but can also be multiple and present anywhere in the body. A presenter shared his surgical approach to the case, emphasizing the importance of removing the entire mass without violating the underlying fascia. A question was raised about the patient's genetic screening and the need for a full body MRI due to the variant of unknown significance. The discussion ended with moderators asking about the surveillance that should be done for this patient.

Genetic Testing, Variant Interpretation, and Myofibromas

The complexities of genetic testing were discussed and the interpretation of variants in genes. Variant in a gene known to cause disease but never seen before can be classified as a variant of unknown significance. However, with time and further research, the interpretation can change. The team emphasized the importance of this in the context of a family with a strong history of developing myofibromas. Also described was the typical pathology of myofibromas, noting their well-circumscribed nature, zonation, and the presence of small vessels. He used a previous case as an example to illustrate his points.

Myofibroma Cases and Genetic Aspects Discussion

Dr. Sherif Emil discussed a case of a child with a large cheek biopsy that resolved spontaneously. He highlighted the challenges of dealing with families who are in denial and don't always attend appointments, which can lead to gaps in the patient's history. Dr. Emil also discussed the genetic aspects of myofibroma, a benign tumor that can spontaneously regress. He mentioned that most mutations are in the PGGFRB gene, which can be heterozygous and associated with autosomal dominant infantile myofibroblastic fibromatosis. The team also noted that some somatic variants have been found, and there is evidence of phenosomatic variance in multiple lesions in the same patient. They concluded by mentioning other associations, such as the Notch 3 gene and cellular myofibromas with gene fusions.

Observation and Management of Vascular Lesions in Infants

The young patient  was born with a lesion that was initially thought to be a human angioma or vascular malformation. The patient underwent a small biopsy at 32 wk prematurely, and the lesion was left to heal by secondary intention. The lesion resolved on its own within 2 y, leaving only a small scar. A moderator suggested that if the parents had decided to observe the lesion, it would have been fine, but it would have been a shared decision. He also mentioned that the patient should be followed up by an oncologist and geneticist, as they have a subspecialty in genetic backgrounds.