Granular cell tumor of the neurohypophysis: Report of a case with intraoperative cytologic diagnosis

Abstract

Cytological techniques including touch and smear preparations are very useful diagnostic modality in the evaluation of central nervous system (CNS) lesions and, in many instances, may be effectively used as the sole modality of tissue preparation for intraoperative consultation. Cytologic preparations offer many advantages over frozen sections for CNS specimens. These include selective examination of multiple areas from small biopsy specimens, superior preservation and details of cellular morphology, fewer artifacts, faster results, and improved costeffectiveness. We describe the cytologic diagnosis of a granular cell tumor (GCT) of the neurohypophysis in a 33-year-old male who presented with headache and blurred vision. CT scan revealed an enlarged sella with a 2.15 3 2.0 cm pituitary lesion. Transsphenoidal resection of the mass was performed and submitted for intraoperative consultation. Smears and touch preparations were made on a portion of the mass that showed uniform polygonal cells with round to ovoid nuclei and abundant eosinophilic granular cytoplasm. An intraoperative cytological diagnosis of ''favor GCT'' was rendered. The histologic sections of the remaining material confirmed the diagnosis. Although GCT of the neurohypophysis is very rare, a specific intraoperative cytological diagnosis is possible. We report the clinical, cytological, and pathological findings of a GCT affecting the neurohypophysis. Diagn. Cytopathol. 2008;36:58-63. ' 2007 Wiley-Liss, Inc.Key Words: granular cell tumor; neurohypophysis; intraoperative smear preparation Granular cell tumors (GCTs) have been reported in many sites of the body including the breast, skin, and larynx. However, head and neck have been the most common sites. GCT has a distinctive appearance on cytology, so that it has been suggested to be an effective method for accurate diagnosis even though some reports focus on the difficulties in cytological differential diagnosis. [1][2][3][4][5][6] Within the central nervous system (CNS), GCTs usually occur as intrasellar and/or suprasellar mass arising from the neurohypophysis or infundibulum. On histologic sections and cytological smears, GCT is composed of nests of large cells with small round to oval nucleus and abundant granular eosinophilic cytoplasm, arranged as individual cells or in clusters. Although the cytology of GCT in other sites has been reported in the English literature, 7-17 to our knowledge, there has been no report on the intraoperative touch/squash cytology of this tumor. We report the first case of GCT of the neurohypophysis diagnosed on cytological preparations during an intraoperative consultation, illustrating the value of intraoperative cytology as a well recognized and reliable diagnostic modality for rapid interpretation and even classification of neuropathologic specimens. Case ReportThe patient is a 33-year-old male with history of progressively worsening headache for 2 years. He presented to our hospital for fever, severe headache, nausea, vomiting, and blurred vision. Cerebrospinal...

Update on Hypophysitis and TTF‐1 Expressing Sellar Region Masses

“…The cytoplasmic granules are PAS‐positive and diastase‐resistant (Figure G). Touch and smear preparations of these tumors highlight the uniform appearance of the tumor cells characterized by uniform nuclei and abundant eosinophilic granular cytoplasm dispersed in a granular background . The tumor shows absent to low mitotic activity, and necrosis is rarely seen.…”

Intraoperative cytology of pituicytomas

“…The varied morphologies of pituicytomas may be due to the fact that there are five subtypes of pituicytes within the neurohypophysis including oncocytic, granular, and “major” (astrocyte‐reminiscent) pituicytes . Though our cohort did not contain any spindle cell oncocytomas and granular cell tumors, granular cell tumors can be identified on cytological preparations by their unique cytoplasmic characteristics . Literature on the cytology of spindle cell oncocytomas is limited, but these tumors appear to show some cytological overlap with pituicytomas, further supportive of the notion that these tumors may be a morphologic variants of the same entity.…”

Cytologic findings of an adult rhabdomyoma in the parapharyngeal space: A report of a case and review of the literature

“…The nucleus/cytoplasmic ratio is low and occasional bare nuclei can be seen in the background. The tumor cells are positive for S‐100 and neuron‐specific enolase, but negative for SMA, desmin, and myoglobin …”

“…The tumor cells are positive for S-100 and neuron-specific enolase, but negative for SMA, desmin, and myoglobin. 11 Oncocytomas are often located in the parotid gland but have rarely been reported in the parapharyngeal area, likely arising from the deep lobe of the parotid gland. 12 The oncocytes have abundant granular eosinophilic cytoplasm and round vesicular to pyknotic nuclei.…”