Prognostic indicators in an aggressive pituitary Crooke's cell adenoma

Crooke Cell Adenoma Confers Poorer Endocrinological Outcomes Compared with Corticotroph Adenoma: Results of a Multicenter, International Analysis

BACKGROUND

Crooke cell adenomas (CCAs) are a rare, aggressive subset of secretory pituitary corticotroph adenomas (sCTAs) found in 5%-10% of patients with Cushing disease. Multiple studies support worse outcomes in CCAs but are limited by small sample size and single-institution databases. We compared outcomes in CCA and sCTA using a multicenter, international retrospective database of high-volume skull base centers.

METHODS

Patients surgically treated for pituitary adenoma from January 2017 through December 2020 were included.

RESULTS

Among 2826 patients from 12 international centers, 20 patients with CCA and 480 patients with sCTA were identified. No difference in baseline demographics, tumor characteristics, or postoperative complications was seen. Microsurgical approaches (60% CCA vs. 62.3% sCTA) were most common. Gross total resection was higher in CCA patients (100% vs. 83%, P = 0.05). Among patients with gross total resection according to intraoperative findings, fewer CCA patients had postoperative hormone normalization of pituitary function (50% vs. 77.8%, P < 0.01) and remission of hypersecretion by 3-6 months (75% vs. 84.3%, P < 0.01). This was the case despite CCA having better local control rates (100% vs. 96%, P < 0.01) and fewer patients with remnant on magnetic resonance imaging (0% vs. 7.2%, P < 0.01). A systematic literature review of 35 studies reporting on various treatment strategies reiterated the high rate of residual tumor, persistent hypercortisolism, and tumor-related mortality in CCA patients.

CONCLUSIONS

This modern, multicenter series of patients with CCA reflects their poor prognosis and reduced postsurgical hormonal normalization. Further work is necessary to better understand the pathophysiology of CCA to devise more targeted treatment approaches.

Pathology of Crooke Cells in the Human Pituitaries: A Timely Review

Crooke cell change was first found in the regressed and suppressed corticotroph (adrenocorticotropic hormone-producing) cells, and now is known to occur in pituitary tumors. The tumor cells of this type can be recognized by morphology with immunohistochemistry, and are well known to predict aggressive behavior such as invasion and rare metastases. This is one of the representative neuroendocrine tumors in the pituitary which is now considered to have malignant potential as proposed in the pancreas and gastrointestinal tracts. It is important to emphasize the pituitary tumor pathology such as Crooke cell change for prognostication and appropriate therapies. This review article describes the evolution from the Crooke cells to Crooke cell tumors which is timely along with the Fifth WHO classification 2022 published online.

Prevalence and clinical characteristics of Crooke's cell adenomas in 101 patients with T-PIT-positive pituitary adenomas: Case series and literature review

PURPOSE

We aimed to perform a retrospective analysis of a rare subtype of corticotroph adenoma, Crooke's cell adenoma, to better understand its clinical features.

METHODS

We collected T-PIT-positive pituitary adenomas and screened Crooke's cell adenomas from January 2020 to December 2021 in our center. Case reports of such tumors were also collected through a literature search. Clinical data such as biochemical tests, imaging examinations, and pathological data of the above cases were analyzed.

RESULTS

A total of 101 T-PIT-positive patients were treated in our center in the last 2 years, and 4 were finally pathologically diagnosed with Crooke's cell adenomas. All of these patients were male with elevated adrenocorticotropic hormone levels, and 50.0% presented with hypercortisolemia, Cushing's syndrome, visual impairment, and headache. The tumor diameter was significantly larger in these 4 patients (37.0 mm) than in the other patients (26.0 mm), and their tumor invasive behavior was more pronounced. Cases reported in the literature were mainly female (72.8%), and the clinical presentation was also dominated by Cushing's syndrome (65.1%) and hormonal dysfunction. Tumors were more common as macroadenomas (33.2 mm) and suprasellar growths (63.8%). The tumor recurrence rate was as high as 55.6%, with 6 cases progressing to pituitary carcinomas and 7.7% of tumor-related deaths. Our further integrated analysis of our center and reported cases revealed that gender, Cushing's syndrome, visual dysfunction, hormonal disorders, and tumor growth characteristics were statistically different in different tumor categories.

CONCLUSION

Crooke's cell adenoma is a tumor subtype with obvious clinical aggressive behavior, and an in-depth analysis of its clinical characteristics may assist in developing a comprehensive treatment plan.

Functioning Crooke Cell Adenomas: Case Series and Literature Review

BACKGROUND

Crooke cell adenomas (CCA) are rare potentially aggressive pituitary adenomas. Data regarding prevalence and clinical course is sparse.

METHODS

Methods consisted of a retrospective review of 59 consecutive functioning corticotroph adenomas (FCA) operated between October 2017-November 2020, and a literature review of CCA publications since 1991.

RESULTS

The prevalence of CCA among FCA at our institution was 8.5% (5/59). In the 4 other surgical cases series, prevalence of CCA ranged between 0%-6.8%. Our patients, 4 women and 1 man, mean age 46±11 years, presented with hypercortisolism (3/5), vision loss (1/5) and incidentally (1/5). All patients had elevated ACTH (151±54 pg/ml) and urinary free cortisol (830±796.5 μg/day) levels. Radiologically, 3 tumors were macroadenomas and 2 had cavernous sinus invasion. All patients achieved biochemical remission at 3 months postoperatively. One patient with a giant pituitary adenoma underwent fractionated radiation for residual tumor. During follow-up (range: 3.1-31.0 months), no patients had evidence of radiological or biochemical recurrence. The literature review (3 case series) and 21 case reports identified 22 FCA with outcome data. Additional treatments included reoperation (50%), radiation (59%), bilateral adrenalectomy (23%) and Temozolomide (36%).

CONCLUSION

We report a higher CCA prevalence among functioning ACTH-adenomas after the implementation of 2017 WHO classification. In our series and the literature, most CCAs were macroadenomas with high ACTH levels. Postoperative outcomes were excellent in our series, while some cases from the literature were refractory to standard treatments. Larger clinical and molecular studies are needed to identify patients at risk.

[Use of chemotherapy in the treatment of aggresive pituitary adenomas]

AIM

To clarify the concept of 'aggressive pituitary adenoma' using analysis of the current concepts, as well as to determine the optimal treatment algorithm for this disease and the place of chemotherapy in this treatment. Pituitary adenomas comprise from 10 to 15% of intracranial neoplasms. Despite the fact that pituitary adenomas are benign neoplasms, in 25-55% of cases they demonstrate invasive growth, growing into the surrounding structures (sphenoid sinus, cavernous sinus, etc.). Due to the lack of a standard definition of aggressive pituitary adenomas (due to the lack of clear criteria for this disease), there are no studies in the literature reporting optimal treatment for this group of patients, except for several publications describing the use of Temozolomide as palliative therapy.

Gamma Knife Radiosurgery in Patients with Crooke Cell Adenoma

BACKGROUND

Crooke cell adenoma is a very rare subtype of pituitary neoplasm that is known to be clinically aggressive. These tumors can secrete adrenocorticotropic hormone or may be endocrinologically silent. We evaluated the effect of Gamma Knife radiosurgery (GKRS) on endocrine remission and tumor control.

MATERIALS AND METHODS

This study comprised 5 patients (2 men, 3 women; median age at GKRS, 55 years [range, 21-65 years]) with pathology-confirmed Crooke cell adenoma treated with GKRS at the Gamma Knife Center of the University of Virginia. The median time interval between transsphenoidal resection and GKRS was 5.8 months. The median margin dose was 25 Gy (range, 18-25 Gy). Median treated adenoma volume was 3.12 mL. Median follow-up was 107 months (range, 44-122 months).

RESULTS

Tumor control was achieved in all patients. Three patients achieved endocrine remission at the last follow-up. The median time interval to cortisol normalization when off of anti-hormone secreting medication was 12 months (range, 6-24 months). Newly developed or worsening endocrinopathy occurred in 3 patients at 6, 15, and 18 months, respectively. Cranial nerve III neuropathy developed in 1 patient. Two patients required bilateral adrenalectomy at 44 months and 50 months, respectively, following GKRS.

CONCLUSIONS

GKRS appears to be a safe and reasonably effective treatment option for Crooke cell adenoma. Multicenter studies with larger numbers of patients are needed to verify these findings.

Aggressive Pituitary Tumor with Crooke's Cells and Invasion of the Posterior Fossa

BACKGROUND

Pituitary adenomas are mostly benign in character and are managed via a transsphenoidal approach in most cases. Crooke's cell adenoma (CCA) is a particular variant accounting for less than 1% of the pituitary adenomas. They have a distinctive histopathologic pattern and behavior.

CASE DESCRIPTION

We present a case of a 56-year-old man with recurrent pituitary adenoma and complicated neurosurgical history. Imaging follow-up showed a suprasellar mass with progressive growth into the posterior fossa. Surgical management via retrosigmoid craniectomy was performed, and histopathology elucidated Crooke's cells.

CONCLUSIONS

CCA is recognized by its local aggressiveness and high recurrence rates. They tend to be locally invasive; however, posterior fossa invasion has not been reported to date. We aim to contribute to the arsenal of differential diagnosis of similar pituitary tumor cases.

Cushing's Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

CLINICALLY SILENT ADRENOCORTICOTROPIC HORMONE-SECRETING CROOKE CELL ADENOMA PRESENTING AS UNILATERAL EAR PAIN

Objective

Crooke cell adenoma (CCA) is a rare tumor of the anterior pituitary. It is highly aggressive and carries significant risk of morbidity and mortality.

Methods

This report focuses on the presentation of this disease process and review diagnosis and treatment. The patient is a 64-year-old male with a history of resected pituitary adenoma of unknown pathology.

Results

The patient underwent serial magnetic resonance imaging surveillance for numerous years without recurrence of tumor, however eventually developed symptoms of worsening left ear pain over 3 weeks that rapidly evolved to include ptosis. Imaging revealed a new pituitary macroadenoma. Urgent surgical resection revealed histopathological diagnosis of CCA. Corticotroph adenomas represent a rare subset of pituitary tumors. Clinically silent pituitary tumors demonstrate relatively higher rates of cavernous sinus invasion (30% versus 18%) and progression or recurrence (34% versus 6%) when compared to nonfunctioning adenomas. In CCA, only 65% of patients have clinical features of Cushing disease at presentation. Twenty-four-hour urinary free cortisol is discussed in the literature as a potential tool, where a value 4 times the upper limit of normal was predictive of higher risk of having Crooke cell changes. With a recurrence rate of up to 60%, multimodal treatment (surgery and radiation) is preferred.

Conclusion

This case highlights early detection and treatment as keys to reducing the risk of morbidity and mortality from CCA. Currently, there are limited tools for identifying patients who are high risk for developing Crooke cell changes. Treatment modalities classically include surgery and radiotherapy. Adjuvant and novel chemotherapies are being explored.

Crooke's cell tumors of the pituitary

Crooke's cell adenomas are a rare type of pituitary neoplasm. They produce adrenocorticotropic hormone causing Cushing's disease or may be endocrinologically silent. These tumors are usually invasive, may exhibit aggressive clinical behavior, and often recur with a low success of cure after reoperation and/or radiotherapy. Due to their rarity, they present great difficulties in assessing prognosis, treatment, and clinical management. Neurosurgeons and physicians dealing with pituitary adenomas diagnosed as Crooke's cell adenomas have to be aware of their potential clinical aggressiveness to plan strict follow-up of patients and eventual multimodality treatment. We review here the published cases of Crooke's cell tumors, as well as the clinical and histopathological characteristics of these unusual neoplasms.

Aggressive pituitary adenomas--diagnosis and emerging treatments

The WHO categorizes pituitary tumours as typical adenomas, atypical adenomas and pituitary carcinomas, with typical adenomas constituting the major class. However, the WHO classification does not provide an accurate correlation between histopathological findings and clinical behaviour. Tumours lacking typical histological features are classified as atypical, but not all are clinically atypical or exhibit aggressive behaviour. Pituitary carcinomas, by definition, have craniospinal or systemic metastases, although not all display classical cytological features of malignancy. Aggressive pituitary adenomas, defined from a clinical perspective, have earlier and more frequent recurrences and can be resistant to conventional treatments. Specific biomarkers have not yet been identified that can distinguish between clinically aggressive and nonaggressive pituitary adenomas, although the antigen Ki-67 proliferation index might be of value. This Review highlights the need to develop new biomarkers to facilitate the early detection of clinically aggressive pituitary adenomas and discusses emerging markers that hold promise for their identification. Defining aggressiveness is of crucial importance for improving the management of patients by enhancing prognostic predictions and effectiveness of treatment. New drugs, such as temozolomide, have potential use in the management of these patients; anti-VEGF therapy, mTOR and tyrosine kinase inhibitors are also potentially useful in managing selected patients.

Improving differential diagnosis of pituitary adenomas

Pituitary adenomas are common tumors arising in adenohypophysial cells or their precursors. For improving control of the disease an early diagnosis is important. Initially considered sporadic tumors, some of them are associated with familial syndromes and their recognition and classification is also required. Morphologically, pituitary adenomas represent a heterogeneous group of tumors with several subtypes and different clinical behavior thus a precise pathological diagnosis is crucial. The simple diagnosis of pituitary adenoma is not satisfactory and the correct classification of histological subtypes may predict aggressiveness in the majority of cases. Although considered not malignant, some of them are clinically aggressive and their recognition remains a challenge. In this paper we present the recent advances in the event of improving early recognition and differential diagnosis of pituitary tumors.

Temozolomide responsiveness in aggressive corticotroph tumours: a case report and review of the literature

Pituitary carcinoma occurs in ~0.2% of resected pituitary tumours and carries a poor prognosis (mean survival <4 years), with standard chemotherapy regimens showing limited efficacy. Recent evidence suggests that temozolomide (TMZ), an orally-active alkylating agent used principally in the management of glioblastoma, may also be effective in controlling aggressive/invasive pituitary adenomas/carcinomas. A low level of expression of the DNA-repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) predicts TMZ responsiveness in glioblastomas, and a similar correlation has been observed in the majority of aggressive pituitary adenomas/carcinomas reported to date. Here, we report a case of a silent pituitary corticotroph adenoma, which subsequently re-presented with Cushing's syndrome due to functioning hepatic metastases. The tumour exhibited low immunohistochemical MGMT expression in both primary (pituitary) and secondary (hepatic) lesions. Initial TMZ therapy (200 mg/m² for 5 days every 28 days-seven cycles) resulted in marked clinical, biochemical [>50% fall in adrenocorticotrophic hormone (ACTH)] and radiological [partial RECIST (response evaluation criteria in solid tumors) response] improvements. The patient then underwent bilateral adrenalectomy. However, despite reintroduction of TMZ therapy (further eight cycles) ACTH levels plateaued and no further radiological regression was observed. We review the existing literature reporting TMZ efficacy in pituitary corticotroph tumours, and highlight the pointers/lessons for treating aggressive pituitary neoplasia that can be drawn from experience of susceptibility and evolving resistance to TMZ therapy in glioblastoma. Possible strategies for mitigating resistance developing during TMZ treatment of pituitary adenomas/carcinomas are also considered.

O-6-methylguanine-DNA methyltransferase (MGMT) immunohistochemical expression in pituitary corticotroph adenomas

BACKGROUND

O-6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that counteracts chemotherapeutic cytotoxicity of alkylating agents such as temozolomide. Low levels of MGMT expression have been shown to correlate with longer survival in glioma patients treated with temozolomide. The same is true in pituitary adenomas.

OBJECTIVE

We investigated the immunohistochemical expression of MGMT in a variety of corticotroph adenoma subtypes to determine the potential utility of temozolomide as a therapeutic agent.

METHODS

The tumors consisted of 40 cases of adrenocorticotropin-secreting pituitary tumors in Cushing disease, 12 Crooke cell adenomas, and 7 subtype I silent corticotroph adenomas. Staining for MGMT was assessed by light microscopy; nuclear reactivity was estimated semiquantitatively as present in < 10%, 10% to 25%, 25% to 50%, 50% to 75%, and > 75% of cells.

RESULTS

Immunoexpression showed no correlation with patient age, sex, tumor size, invasiveness, or recurrence in patients with Cushing disease. Among adrenocorticotropin-secreting adenomas associated with Cushing disease, most invasive (60%) and recurrent (86%) tumors showed low MGMT immunopositivity, defined as < 25%. Most (75%) Crooke cell adenomas exhibited an MGMT immunoreactivity of ≤ 50%. All subtype I silent corticotroph adenomas showed < 10% MGMT staining.

CONCLUSION

Our descriptive findings of low MGMT expression in adrenocorticotropin-producing pituitary adenomas, particularly aggressive tumors, suggest that they may be suitable candidates for temozolomide therapy.

Atypical, invasive, recurring Crooke cell adenoma of the pituitary

We report the case of a 49-year-old woman presenting with Cushing disease and visual disturbance. An atypical, aggressive, invasive pituitary tumor regrew despite several surgeries. Detailed morphologic investigation by histology, immunohistochemistry and electron microscopy documented a Crooke cell adenoma, a rare form of ACTH-producing pituitary tumor. Recognition of such adenomas is of importance given their aggressive behavior and tendency to recur. More studies are needed to explain the pathobiology of this not invariably functional pituitary adenoma.