Double pituitary adenomas in a large surgical series

Abstract

Purpose: To explore the incidence of double pituitary adenomas in a tertiary center for pituitary surgery and asses their clinical, imaging and histopathological features.

Methods: The medical records of the patients operated on for pituitary tumors at the Department of Neurosurgery of Military Institute of Medicine in Warsaw, Poland between the years 2003 and 2018 were retrospectively analyzed. Among the 3270 treated patients, the diagnosis of double pituitary adenoma was established in 22 patients. Clinical, laboratory, detailed histopathological and diagnostics imaging data were collected and analyzed.

Results: There were 21 cases of synchronous and one case of asynchronous double pituitary adenoma. The main clinical finding was acromegaly (12/22) followed by Cushing's disease (3/22). The diagnosis of synchronous double pituitary adenoma was suspected in the preoperative MRI in 11 patients. In the remaining patients the diagnosis of contiguous double pituitary adenoma was confirmed in the histopathological examination. There was no predilection for gender and the mean observation time was 74.2 months. In one case of Cushing's disease the occurrence of double pituitary adenoma led to the initial failure of achieving hormonal remission. One patient presented with double pituitary adenomas as a manifestation of Carney complex.

Conclusions: Double pituitary adenoma is a rare entity that can pose a significant challenge especially in the setting of Cushing's disease. Careful inspection of preoperative MRI and diagnostic work-up before transsphenoidal surgery and thorough histopathological microscopic examinations with immunohistochemical staining for all pituitary hormones is essential for establishing the diagnosis of double pituitary adenoma.

Keywords: Double pituitary adenoma; Immunohistochemistry; Surgical treatment; Transsphenoidal approach.

Fig. 1

Case no. 1, coronal T1 (upper row) and coronal T2 (lower row) weighted MR imaging identified two clearly separate pituitary macroadenomas with different signal intensity. Left and right arrows indicate respectively somatotroph and gonadotroph tumors. Both tumors were separated by flattened pituitary gland (visible on T1 weighted MR imaging as a hyperintensive band between the two tumors and confirmed during transsphenoidal operation)

Fig. 2

Case no. 2: a coronal T1 weighted MRI after Gd-DTPA demonstrates two clearly separate pituitary adenomas with flattened normal pituitary gland (arrow), b and c coronal and axial T2 MRI show gonadotroph macroadenoma with cystic degeneration (on the left side) and solid somatotroph adenoma (on the right side)

Fig. 3

Case no. 9: a coronal T1 weighted MRI after Gd-DTPA revealed two clearly separate pituitary adenomas, b left arrow indicates intrasellar gonadotroph pituitary macroadenoma and right arrow shows cystic somatotroph macroadenoma with suprasellar extension

Fig. 4

Case no. 7, coronal T1 weighted after Gd-DTPA (left image) and T2 weighted (right image) MR imaging revealed invasive pituitary macroadenoma invading sellar floor

Fig. 5

Contiguous double pituitary adenoma: case no. 7, Cushing disease. Pathomorphological evaluation: a H&E, b IHC for GH, c IHC for ACTH, d Electron microscopy, original magnification ×  9700

Fig. 6

Contiguous double pituitary adenoma: case no. 17, acromegaly. Pathomorphological evaluation: a H&E, b IHC for GH, c IHC for PRL, d IHC for alpha subunit, e IHC for ACTH, f Electron microscopy original magnification × 9700

Fig. 7

Case no. 12: a arrow indicates somatotroph pituitary macroadenoma removed with its pseudocapsule during first transsphenoidal operation (year 2008), b postoperative MR image (after first operation), remission of the acromegaly was achieved, c arrow indicates a new pituitary adenoma in the right lateral wing of the pituitary gland (year 2011), d postoperative MR image (after second operation)

Fig. 8

Separate tumors identified intraoperatively with different histopathological diagnosis: case no. 19, Cushing disease. Pathomorphological evaluation: I. Tumor on the right side: a H&E, b IHC for PRL, c IHC for ACTH, d IHC for alpha subunit; II. Tumor on the left side: e H&E, f IHC for PRL, g IHC for ACTH, h Electron microscopy, original magnification × 9700

Fig. 9

Case no. 13, T1 weighted image after GD-DTPA. Separate tumors were identified in the MR imaging and intraoperatively, the arrow indicated flattened pituitary gland

Fig. 10

Separate tumors identified in the MRI and intraoperatively with similar histopathological diagnosis: case no. 13, NFPA. Pathomorphological evaluation: I. Tumor on the right side: a H&E, b IHC for FSH, c IHC for LH, d IHC for alpha subunit, e Electron microscopy, original magnification × 9700; II. Tumor on the left side: f H&E, g IHC for FSH, hIHC for LH, i IHC for alpha subunit, j Electron microscopy, original magnification × 9700

Fig. 11

Case no. 21, a and b coronal T1 weighted after GD-DTPA (left image) and T2 weighted (right image) MR imaging of the pituitary gland of the patient with diagnosed Carney complex. Arrows indicate two clearly separate microadenomas confirmed during operation and histological examination

Fig. 12

Separate tumors identified in the MRI and intraoperatively with similar histopathological diagnosis: case. no 21, acromegaly, Carney complex. Pathomorphological evaluation: I. Tumor on the right side: a H&E, b IHC for GH, c IHC for PRL, d IHC for alpha subunit, e Electron microscopy, original magnification × 7400; II. Tumor on the left side: f H&E, g IHC for GH, h IHC for PRL, i IHC for alpha subunit, j Electron microscopy, original magnification × 9700