PMC8513866_01
MRI of the pituitary sarcoma arising from a pituitary adenoma. Axial T2 FLAIR (A) and axial (B), coronal (C), and sagittal (D) T1-weighted with contrast MRI of tumor measuring 2 x 2.7 x 2 cm3 at the time of diagnosis. The same sections are shown for the tumor three years later, prior to surgical resection, measuring 3.3 x 3.0 x 2.6 cm3
(E-H).
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AP x CC) was identified ( Figures 1A-D ). Additionally, the lesion encased two-thirds of the left cavernous carotid artery along with significant mass effect on the optic chiasm. The mass then was measuring 3.3 x 3.0 x 2.6 cm3 with a significant increase in mass effect on adjacent structures ( Figures 1E-H ).
Histopathological and immunohistochemical characterization of the pituitary sarcoma arising from a pituitary adenoma. H&E stains of the pituitary adenoma (A) and a concurrent sarcoma which has brisk mitotic activity and necrosis (B). The adenoma is immunoreactive for synaptophysin (C), ACTH (D) and GH (E) whereas the sarcomatous component has lost synaptophysin stain (C), but become patchy positive for myogenin (F), desmin (G), and diffusely positive for p53 (H).
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Histological studies of the resected tumor revealed pituitary adenoma with the loss of acinar architecture and ribbon-like arrays ( Figure 2A ). In addition, there was a presence of spindle-like cells with necrosis and brisk mitotic activity ( Figure 2B ). Immunohistochemical stain for synaptophysin, adrenocorticotropic (ACTH) and growth hormone (GH) was positive for the pituitary adenoma but not the sarcomatous component ( Figures 2C-E ). Instead, the sarcomatous component was positive for desmin, myogenin, and p53, confirming the diagnosis of a pituitary RMS arising from the pituitary adenoma ( Figures 2F-H ).