case_images: PMC9897700_01
case_images: Computed tomography scan of the abdomen and pelvis showing an 18 x 25 cm left retroperitoneal mass: axial (A) and sagittal (B) view (white arrow).
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case_images: PMC9897700_01_cureus-0015-00000033446-i01.jpg
case_images: FIG1
case_images: A 60-year-old male, with no relevant medical history, was diagnosed in June 2019 with a 25 cm retroperitoneal mass following a progressive increase in scrotal and abdominal volume over a period of six months (Figure 1).
case_images: Levels of albumin-corrected serum calcium and response to therapy.
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case_images: PMC9897700_01_cureus-0015-00000033446-i02.jpg
case_images: FIG2
case_images: He maintained a close follow-up at our clinic, with serum calcium levels between 11.6 mg/dL and 15.8 mg/dL (Figure 2).
case_images: (A) Dedifferentiated area of liposarcoma (hematoxylin & eosin stain). (B) MDM2 positivity in the dedifferentiated area of liposarcoma. (C) Weak positivity for 1alpha-hydroxylase expression in liposarcoma tissue. (D) Positivity for 1alpha-hydroxylase expression in normal human kidney.
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case_images: PMC9897700_01_cureus-0015-00000033446-i03.jpg
case_images: FIG3
case_images: Surgical resection of the tumor was performed in September 2019, and pathology revealed a dedifferentiated liposarcoma measuring 45 x 40 x 29 cm (Figure 3A). The heat-mediated antigen retrieval was Ventana CC1 for 64 minutes for anti-CYP27B1 and 48 minutes for anti-MDM2 (Figure 3B). Immunohistochemical analysis with the antiserum for 1alpha-hydroxylase showed expression for the enzyme in liposarcoma cells (Figure 3C) and in renal proximal tubule epithelial cells (Figure 3D).