Contributed by Elia Guadagno1, Domenico Solari2, Sara Pignatiello1, Teresa Somma2, Roberta Sgariglia3, Gennaro Ilardi1, Paolo Cappabianca2, Marialaura Del Basso De Caro1
1Department of Advanced Biomedical Sciences, Pathology Section;
2Department of Neurosciences, Reproductive and Odontostomatological Sciences, Division of Neurosurgery;
3Department of Public Health- University of Naples Federico II, Via Pansini 5, 80131 Naples- Italy
CLINICAL HISTORY AND IMAGING
The patient referred to the neurosurgeon in October 2015, complaining polyuria, polydipsia and polyphagia, associated with violent headache, unresponsive to anti-inflammatory therapy, vomit and loss of consciousness. After the onset of visual impairment in the left eye, the patient underwent MRI scan that revealed a giant irregular suprasellar mass (max diam 3.5 cm) moving from the level of the infundibular area within the third ventricle chamber; these lesion showed (Fig. 1A) strong and in-homogenous enhancement post-GAD and little calcified spots were noted within its bulk. Pituitary hormonal levels were within the normal range. In May 2016 the patient underwent surgery, by mean of endoscopic endonasal approach: at this time, due to the hard consistency, the tight adherences of the tumor and the narrow and deep corridor lesion has been only partially removed. As per protocol a second transcranial approach was scheduled, nevertheless three months later, hydrocephalus developed and urgent ventricle-peritoneal shunt procedure was required, although residual tumor was stable. Six months thereafter a new MRI disclosed a slight enlargement of tumor (volume increase was 30% more than the prior exam), so that transcranial transcortical-transventricular approach was adopted to remove the lesion. Extent of removal at that time was near-total (>90%), nevertheless, patient died few weeks later due to severe meningitis that complicated with multi-organ failure.
Microscopic examination of the first surgical sample revealed a neoplasm characterized by solid growth of squamous epithelium with pseudopapillary pattern (Fig. 1B), with vague peripheral palisading and in absence of wet keratinization, calcification and cholesterol accumulation. Pseudopapillary architecture was created by the presence, within the solid lesion, of clefts surrounded by apoptotic cells (Fig. 1C, arrow). Many small whorls were often present (Fig. 1C*). Mild atypia was observed (Fig. 1D,*).
In the second surgical sample, the neoplasm showed similar morphological features in addition to more severe atypia and evident HPV-like dysplastic changes (cells with perinuclear halo and atypical nuclei, sometimes with binucleation) (Fig. 1E). Rare mitotic figures were detected and no signs of clear malignancy were evident.
Molecular tests did not confirm the presence of HPV infection and detected BRAF-V600E mutation.
In both specimens, immunohistochemical analysis showed intense nuclear and cytoplasmic reactivity to p16 (Fig. 1F) in >75% of neoplastic cells, nuclear positivity to p53 (Fig. 1G) in 50% of neoplastic cells and reactivity to Beta-catenin that was located at the tumor cell membranes (Fig. 1H). Ki67 cellular proliferation index was low and most of the signal was located in the basal cells layer (Fig. 1I) in both samples. What is your diagnosis?