Congenital Rhabdomyosarcoma Presenting as a Neck Mass at Birth

Abstract

Rhabdomyosarcoma is a malignant tumor of the soft tissues which preferentially affects the pediatric population. Neonatal rhabdomyosarcoma is rare, and much of the published literature concerning this entity consists of isolated case reports and small case series. Recent work involving the classification of rhabdomyosarcoma has helped to delineate prognostic information based on gene rearrangements. Here, we present a case of congenital rhabdomyosarcoma seen in utero which manifested as a neck mass at birth and was found to harbor a favorable gene fusion.

Infantile Rhabdomyosarcomas With VGLL2 Rearrangement Are Not Always an Indolent Disease

“…Tumor cells do not display significant pleomorphism or anaplasia, although some mitotic activity may be seen. 3,5 They tend to infiltrate within the skeletal muscle, 2 which was also observed in our cases, and to encase neurovascular structures (Fig. 1B, 2B).…”

“…[15][16][17] Survival data in ssRMS reported before the discovery of VGLL2/NCOA2 rearrangements and MYOD1 mutations are difficult to interpret. 18,19 In more recent studies, follow-up information was available for 19 cases of ssRMS with a documented VGLL2 and/or NCOA2 rearrangement [2][3][4][5][6] (Supplemental Digital Content 1-Tables ST10, http://links.lww.com/PAS/B109). With a median follow-up of 29 months (range, 7 mo to 13 y), 2 patients experienced local recurrence, 2 but no metastatic events were reported, and all patients were alive with no evidence of disease at follow-up.…”

“…Congenital/infantile sclerosing and spindle-cell rhabdomyosarcomas (ssRMS) with VGLL2 and/or NCOA2 rearrangement represent a rare distinct subtype of rhabdomyosarcoma (RMS) 1,2. All cases reported to date in the literature for which follow-up data are available (n=19, median follow-up: 29 mo) have shown favorable outcomes and no metastatic events have been described 1–6. Conversely, we identified 4 cases of VGLL2- rearranged RMS with several years’ follow-up that showed metastatic progression, including death due to the disease in 2 cases.…”

“…1,2 All cases reported to date in the literature for which follow-up data are available (n = 19, median follow-up: 29 mo) have shown favorable outcomes and no metastatic events have been described. [1][2][3][4][5][6] Conversely, we identified 4 cases of VGLL2rearranged RMS with several years' follow-up that showed metastatic progression, including death due to the disease in 2 cases. We show that disease progression may be accompanied by sarcomatous high-grade transformation.…”

Congenital spindle cell rhabdomyosarcoma

“…The existing reports of this entity lack detailed clinical information including responses to therapy and extent of surgical resection. Table contains a summary of the four patients in our series and the previously reported cases of spindle cell RMS in infants less than 1‐year old . Of the 14 previously reported cases, nine cases (64%) occurred in truncal locations (back, chest wall), and four were head and neck locations (29%) (orbital, base of tongue, neck) with only one reported case occurring in an extremity.…”