Brain Pathology Case of the Month - October 2013

Contributed by Thor D. Stein1, Yang-seok Chae2, Namehee Won2, Jeong-hyun Lee2, and E. Tessa Hedley-Whyte1
1Massachusetts General Hospital, Harvard University, Boston
     2Anam Hospital, Korea University Seoul, Korea


This 34 year-old man presented with a five month complaint of bitemporal hemianopsia. For two years he had decreased visual acuity and increased intraocular pressure treated medically. Magnetic resonance imaging revealed widening of the pituitary fossa and an intrasellar, dumbbell shaped, enhancing mass 3 cm in diameter, extending into the suprasellar region pushing on the optic chiasm (Figure 1). The mass was partially excised, but regrew in three months causing the same symptoms. A second excision was performed. Three months later the tumor again regrew with extension into the sphenoid sinus, and the patient underwent a third excision. Following surgery, the patient was given radiotherapy and one cycle of chemotherapy (adriamycin, dacabarzine, and ifosfamide). Follow-up PET-CT three months after the third surgery showed no evidence of hypermetabolic residual/recurrent tumor.


Both the first and second excisions show small, spindled cells with interdigitating elongated eosinophilic cells (Figure 2). In addition, there are scattered glandular groups of monomorphic round cells with large amounts of eosinophilic cytoplasm (Figures 2 and 3). In some areas there are primitive cells with small round nuclei, scant cytoplasm, and numerous mitoses and apoptotic cells (Figure 3) and occasional cells with striations (Figure 4). The small spindle cells and striated cells are positive for desmin and have nuclear positivity for myogenin (Figure 5) and myo-D1 (not shown). The islands of monomorphic large eosinophilic cells are positive for synaptophysin (Figure 6) and ACTH (Figure 7) and negative for prolactin (Figure 8). They are also positive for chromogranin, CK 5.2, pan keratin, and NSE (not shown).

The third excision reveals similar findings (not shown). The tumor invades the sphenoid sinus and is positive for Myo-D1. The Ki-67 proliferation index is markedly elevated within the primitive, anaplastic regions. Again, there are elongated striated cells and foci of anaplastic small cells as well as admixtures of the large eosinophilic cells, which are positive for keratin, synaptophysin, and ACTH (not shown). What is your diagnosis?


International Society of Neuropathology