Pituitary Carcinoma: An Ultrastructural Study of Eleven Cases
Bibliographic record
Abstract
Pituitary carcinomas are very rare. Defined as adenohypophysial tumors that undergo craniospinal and/or systemic metastasis, most are PRL- or ACTH-producing. Their ultrastructural features, particularly relative to benign adenomas of similar functional type, have not been sufficiently explored. Eleven cases of immunohistochemically characterized pituitary carcinoma with documented cerebrospinal and/or systemic metastases were collected from various institutions and studied by transmission electron microscopy. The tumors were surgically removed from 7 women and 4 men ranging in age between 28 and 74 years (mean, 50 years). All were endocrinologically functioning. Six tumors secreted PRL; three were ACTH-producing; one each was GH/PRL- and TSH-producing. The patients with the ACTH-producing tumors had all presented with Cushing's disease and two of them had undergone adrenalectomy (Nelson syndrome). In most cases significant cellular atypia and mitotic activity were observed. In terms of morphologic features of functional differentiation, electron microscopy revealed that in 9 cases the tumor cells maintained at least some ultrastructural markers of their basic phenotype. A unique feature in 2 ACTH carcinomas was the variable admixture of smooth endoplasmic reticulum with intermediate (cytokeratin) filaments. In 2 cases, both PRL-producing carcinomas, the cell type comprising the tumor could not be identified on an ultrastructural basis alone. Ultrastructural investigation of pituitary carcinomas confirms their endocrine nature and, in most but not all cases, reveals their functional differentiation. Despite the diagnostic utility of electron microscopy in the assessment of these rare tumors, the distinction of pituitary carcinoma from pituitary adenoma cannot be firmly made on ultrastructural grounds alone.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.003 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".