Juvenile xanthogranuloma involving concurrent iris and skin: Clinical, pathological and molecular pathological evaluations

Abstract

Purpose: To report a case of juvenile xanthogranuloma involving the iris and skin that clincally was diagnosed with an obvious cutaneous lesion.

Observations: A four month-old girl with hyphema and increased intraocular pressure of the left eye persisting for 2 weeks. A suspicious yellow-brown mass with nodular surface and traversed by irregular vascularization was noted on the inferior iris surface. Ultrasound biomicroscopy (UBM; 35 MHz) of the mass revealed multiple nodular irregular hyperreflective lesions in the peripheral iris. Using a biopsy of an obvious cutaneous abdominal skin lesion a diagnosis was made based on histopathological analyses. The biopsy showed dense dermal infiltrate consisting of foamy histiocytes. Additional stains revealed CD68 positivity and CD1a and S100 negativity. This mass revealed histopathologic features identical to juvenile xanthogranuloma and was concurrent with the iris lesion. Next-generation sequencing using Ion AmpliSeqTM Cancer Hotspot Panel revealed a missense mutation of FGFR3 (p.F386L).

Conclusion and importance: The diagnosis of a xanthogranuloma of the iris with hyphema can be made easier in patients with obvious cutaneous lesions as described in our case. The significance of FGFR3 mutation in association with JXG is unknown and should be further investigated.

Keywords: Cutaneous lesion; FGFR3 mutation; Iris; Juvenile xanthoganuloma; Ultrasound biomicroscopy.

Fig. 1

Clinical evaluation of the iris lesion. A. A Yellow-brown mass with irregular vascularization at the inferior part of the iris surface; became visible after ten days of treatment (dorzolamid/timolol and topical steroid). B. Ultrasound biomicroscopy of the anterior segment revealing multiple nodular hyperreflective heterogenous mass in the peripheral iris between 2 and 7 o'clock, growing into the anterior chamber angle and to the corneal endothelium (section at 5 o'clock). C. After 2 month of high-dose corticosteroid treatment iris lesion decreased completely without recurrence of hyphae or iritis. D. Ultrasound biomicroscopy confirming decrease of iris lesion (section at 5 o'clock).

Fig. 2

Histopathological analyses of the skin lesion. A. Abdominal skin lesion used for histopathological evaluation. B. Hematoxylin and eosin staining (20x) showing dense dermal infiltrate consisting of histiocytes, some lymphocytes and plasma cells. Touton giant cells were not detected. A 60× magnification of the respective area is shown in the lower right corner. C. Positive CD68 staining (20x) for confirmation of the histiocytic phenotype. D. Negative CD1a and S100 staining (20x) ruling out Langerhans cell histiocytosis.

Fig. 3

Molecularpathological analyses of the skin lesion. Next-generation sequencing using Ion AmpliSeqTM Cancer Hotspot Panel v2 revealing FGFR3 (p.F386L) missense mutation.