case_images: PMC10781526_01
case_images: CT scan showing renal/pararenal masses in the patient. (a) Abdominal coronal plane, showing masses with near-total compression/infiltration of the kidneys. Remaining renal structures of the left kidney are visible in this section. (b) Transverse plane of the same patient.
case_images: CRIHEM2024-3502887.001.jpg
case_images: PMC10781526_01_CRIHEM2024-3502887.001.jpg
case_images: fig1
case_images: Sonography and a CT scan showed bilateral pararenal/renal masses (Figure 1), whereby the renal pelvis could not be adequately evaluated.
case_images: Bone marrow biopsy reveals mastocytosis. (a) H&E stain shows a patchy distribution of areas with atypical mast cell infiltrates, concentric fibrosis (dashed line), and granulocyte-rich areas (bold line). Trabeculae shows signs of beginning osteosclerosis with focal spikes and paratrabecular apposition of new bone (osteosclerosis grade 1). (b) Gomori stain damasks a diffuse and dense increase in reticulin with extensive intersections, occasionally with focal bundles of thick fibres, associated to focal myelofibrosis (MF-2), particularly in the mast cell-rich area. (c) H&E stain shows infiltrates of atypical spindle-shaped mast cells without metachromatic granules and without blast-like appearance. (d) Giemsa stain exposes atypical mast cells, some of which still contain metachromatic granules. (e) Immunohistochemical staining for CD117 highlights atypical mast cell infiltrates (encircled by the dashed line). (f) Immunohistochemical staining for MPO highlights patchy granulocyte-rich area (encircled by a bold line). (g) Expression of mast cell tryptase is present within the atypical mast cell aggregates. (h) CD25 expression emphasizes the atypical immunophenotype of the mast cells.
case_images: CRIHEM2024-3502887.002.jpg
case_images: PMC10781526_01_CRIHEM2024-3502887.002.jpg
case_images: fig2
case_images: Furthermore, there was concomitant patchy BM fibrosis grade MF-2 according to WHO (Figure 2).
case_images: Biopsy of the renal mass reveals extramedullary hematopoiesis and only few mast cell aggregates. (a, b) H&E stain shows extramedullary hematopoiesis. The single arrow in panel (a) illustrates megakaryopoiesis and double arrows in panel (b) indicate a mature group of erythroblasts. (c, d) Giemsa stain shows extramedullary granulopoiesis. Arrows in panel (c) depict segmented mature granulocytes, and arrows in panel (d) highlight intermixed atypical spindle-shaped mast cells. (e) Immunohistochemical staining for CD34 highlights vascular endothelium and shows absence of blasts. (f) Immunohistochemical staining for CD117 reveals mast cell hotspots. (g) Mast cell tryptase supports the presence of mast cells. (h) Only few mast cells show expression of CD25.
case_images: CRIHEM2024-3502887.003.jpg
case_images: PMC10781526_01_CRIHEM2024-3502887.003.jpg
case_images: fig3
case_images: Timeline of serum creatinine (reference range 0.5-0.9) and tryptase (reference range <1.14) levels between time of initial presentation (d0) and time of death (approx. d180).
case_images: CRIHEM2024-3502887.004.jpg
case_images: PMC10781526_01_CRIHEM2024-3502887.004.jpg
case_images: fig4
case_images: Serum creatinine and tryptase levels between emergency unit presentation and time of death are provided in Figure 4.