The First Case Of The Myopericytomatosis Of The Foot With RAF1 Rearrangement Involving Intron 7 (ATG7-RAF- 1)

Introduction/Objective

Myopericytomatosis, recently described by Yin P. Hung et al [1], is an extremely rare myopericytic proliferation with only less than 15 reported cases in the English literature. This neoplasm has been described as dermal or subcutaneous well-circumscribed nodules composed of ovoid to spindled cells in a perivascular distribution, with no significant necrosis, atypia or mitosis. It usually involves the lower extremities with the ankle being the most common location. Next-generation DNA sequencing (NGS) in all the previously reported cases exhibited PDGFRB alterations with no BRAF, NOTCH, and/or GLI1 alterations [1].

Methods

We report a 47-year-old man who presented multiple well-encapsulated nodules on his right foot that were localized to the fascia/subcutaneous fat by MRI; fibromas were the main radiologic differential diagnosis.

Results

The biopsy and subsequent excisional specimens showed diffuse involvement by numerous discrete myopericytomatous nodules composed of bland spindled to ovoid cells. Immunohistochemical staining demonstrated that the myopericytic cells are strongly positive for SMA, focally positive for caldesmon with a patchy cytoplasmic CD99 staining. Ki-67 showed a low proliferation rate of 1–2%. Desmin, CD31, CD34, HHV8, STAT6, S100, HMB45, and Melan-A immunostains were negative. The diagnosis of myopericytomatosis was made. The NGS revealed that the tumor cells are positive for RAF1 rearrangement involving intron 7 (ATG7-RAF-1) with no other findings, including PDGFRB alterations.

Conclusion

Myopericytomatosis is an exceedingly rare entity with most of the previously reported cases involving the lower extremities and only two cases involving the foot. In all the prior cases, the PDGFRB mutation N666K was noted [1]. We report the first case of RAF1 rearrangement in myopericytomatosis of the foot with no other genetic alterations.

Longitudinal health surveillance in a cohort of Gulf War veterans 18 years after first exposure to depleted uranium

As part of a longitudinal surveillance program, 35 members of a larger dynamic cohort of 79 Gulf War I veterans exposed to depleted uranium (DU) during combat underwent clinical evaluation at the Baltimore Veterans Administration Medical Center. Health outcomes and biomonitoring results were obtained to assess effects of DU exposure and determine the need for additional medical intervention. Clinical evaluation included medical and exposure histories, physical examination, and laboratory studies including biomarkers of uranium (U) exposure. Urine collections were obtained for U analysis and to measure renal function parameters. Other laboratory measures included basic hematology and chemistry parameters, blood and plasma U concentrations, and markers of bone metabolism. Urine U (uU) excretion remained above normal in participants with embedded DU fragments, with urine U concentrations ranging from 0.006 to 1.88 μg U/g creatinine. Biomarkers of renal effects showed no apparent evidence of renal functional changes or cellular toxicity related to U body burden. No marked differences in markers of bone formation or bone resorption were observed; however, a statistically significant decrease in levels of serum intact parathyroid hormone and significant increases in urinary calcium and sodium excretion were seen in the high versus the low uU groups. Eighteen years after first exposure, members of this cohort with DU fragments continue to excrete elevated concentrations of uU. No significant evidence of clinically important changes was observed in kidney or bone, the two principal target organs of U. Continued surveillance is prudent, however, due to the ongoing mobilization of uranium from fragment depots.