2025 Poster Presentations
P287: TRANSFORMATION VERSUS ASCERTAINMENT BIAS OF A SUPRASELLAR LESION- A HISTOPATHOLOGIC CONUNDRUM: BRAF V600E POSITIVE PAPILLARY CRANIOPHARYNGIOMA VERSUS RATHKE'S CLEFT CYST WITH SQUAMOUS METAPLASIA
Hailey Mattheisen, MS; Samon Tavakoli, MD; E. Kelly S. Mrachek, MD; Stephanie Cheok, MD; Nathan Zwagerman, MD; Medical College of Wisconsin
Background: Diagnosis of cystic sellar lesions is crucial for establishing appropriate treatment. Differentiating craniopharyngiomas (CPs) and Rathke’s cleft cysts (RCCs) often pose difficulties due to overlapping clinical, imaging, and histological features. RCCs with squamous metaplasia (SM) may serve as a transition state to ciliated CPs, complicating the differential diagnosis between the two. Molecular markers specific to RCCs and CPs serve as potential diagnostic tools and therapeutic targets. BRAF V600E, a mutation in early carcinogenesis, is a marker to differentiate papillary CPs from cases of cystic pituitary lesions with metaplastic changes. This study highlights a case of RCC recurrence and transformation to a papillary CP, prompting a systematic review to describe clinical presentation, radiographic findings, histopathologic features of RCCs and CP that predict recurrence.
Methods: A systematic review was performed with adherence to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Using the PubMed/Medline and Cochrane Library databases, a search string was created with the keywords “Rathke cleft cyst transformation OR (Rathke cleft cyst AND craniopharyngioma) OR (RCC to craniopharyngioma) OR (Rathke cleft cyst to craniopharyngioma) OR (Rathke AND craniopharyngioma)”. After review by two authors, 5 studies that met criteria were included.
Results: Our systematic review was prompted by a case of a 74-year-old male with a suprasellar lesion initially diagnosed as RCC with SM. The patient underwent repeat resection due to symptomatic recurrence with additional neuropathologic testing positive for BRAF V600E mutation and diagnosis of papillary CP. Only 1 study in our review tested for BRAF V600E and/or B-catenin for initial RCCs. Our review included 4 males and 1 female, with an average age of 46.2 years (range 36-61). All patients initially presented with visual acuity loss or bitemporal hemianopsia, and endocrine evaluation revealed panhypopituitarism in two patients and normal pituitary function in three. MRI studies suggested an initial diagnosis of RCC with suprasellar invasion in 4 patients. All patients underwent extended endoscopic transsphenoidal approach for resection of their cystic lesions. Post-operatively, 3 patients experienced recurrence from residual tumor with an average rate of 9.4 (1-34) months. Histological examination on initial and second surgical resections revealed SM in 40% and 60% of the patients respectively, and RCC recurrence with transformation to craniopharyngiomas (2 adenomatous CPs, 2 papillary CPs, 1 ciliated CP).
Discussion: The spectrum from RCC to RCC with SM to CP is not well understood. Not all patients with RCC progress to these more aggressive subtypes and currently there is no predictor on imaging or histopathology of transformation. This seems to be a rare event with five recorded cases in the literature based on our in-depth systematic review. While rare, this transformation may also be understudied. The purpose of our review was to indicate the potential for BRAF V600E testing in sellar lesions suspected of RCC or CP. This could assist with differential diagnosis and avoid radical resection of true RCCs or predict recurrence/ transformation to CPs.