Double Adenomas of the Pituitary

A Collision Tumor of Pit-1/SF-1-positive Double Pituitary Adenoma and a Craniopharyngioma Coexisting with Graves' Disease

Double or multiple pituitary adenomas expressing different types of transcription factors and collision tumors of pituitary adenomas and craniopharyngiomas are rare. In this report, we present a case of pituitary adenoma of two different cell populations, Pit-1 and SF-1, and an adenoma and craniopharyngioma collision tumor with coexisting Graves' disease. The patient had a 16-mm pituitary tumor with pituitary stalk calcification and optic chiasm compression but no visual dysfunction. Based on hormonal profile results, the tumor in the sella was considered a nonfunctioning pituitary adenoma; nevertheless, the pituitary stalk was invaded by a different lesion, which was later confirmed to be a craniopharyngioma. Using an endoscopic endonasal approach, the pituitary adenoma was removed; however, a small remnant remained medial to the right cavernous sinus. Because the pituitary stalk lesion was isolated from the pituitary adenoma, it was preserved to maintain pituitary function. Three years after the initial surgery, the patient suffered from Graves' disease and was treated with antithyroid medications. However, the intrasellar residual and pituitary stalk lesions gradually increased in size. A second surgery was performed, and the residual intrasellar and stalk lesions were completely removed. As per the initial and second histopathologies, the pituitary adenoma comprised different cell groups positive for thyroid-(TSH) and follicle-stimulating hormones, and each cell group was positive for Pit-1 and SF-1. The pituitary stalk lesion was an adamantinomatous craniopharyngioma. We believe that TSH-producing adenoma was involved in the development of Graves' disease or that treatment for Graves' disease increased TSH-producing adenoma.

Multiple tumorous lesions of the pituitary gland

PURPOSE/OBJECTIVE

Multiple tumorous lesions in one pituitary gland are rare and mostly described in case reports. Their incidences and combinations are defined in larger collectives. Therefore, we analyzed our large collection for double tumors and combinations of tumors, cysts, and inflammation.

METHODS

The German Registry of Pituitary Tumors, including cases from 1990 to 2018, served as the database. Our collection comprises a total of 16,283 cases up until the end of 2018. Of these cases, 12,673 originated from surgical and 3,610 from autopsy material. All specimens were fixed in formalin and embedded in paraffin. The sections were stained with hematoxylin-eosin and PAS. Monoclonal (prolactin, TSH, FSH, LH, and α subunit) or polyclonal (GH and ACTH) antibodies were used to detect pituitary hormones in the lesions. Since 2017, antibodies against the transcription factors Pit-1, T-Pit, and SF-1 have been used in difficult cases. The criteria of the 2017 WHO classification have been basic principles for classification since 2018 (Osamura et al. 2017). For differentiation of other sellar tumors, such as meningiomas, chordomas, or metastases, the use of additional antibodies was necessary. For these cases, it was possible to use a broad antibody spectrum. Autopsy pituitaries were generally studied by H&E and PAS sections. If any lesions were demonstrated in these specimens, additional immunostaining was performed.

RESULTS

Multiple tumorous lesions with more than one pituitary neuroendocrine tumor (PitNET) respectively adenoma make up 1.4% (232 cases) in our collection. Within the selected cases, synchronous multiple pituitary neuroendocrine tumors (PitNETs) account for 17.3%, PANCH cases (pituitary adenoma with neuronal choristoma) for 14.7%, PitNETs and posterior lobe tumors for 2.2%, PitNETs and metastases for 5.2%, PitNETs and mesenchymal tumors for 2.6%, PitNETs and cysts for 52.2%, and PitNETs and primary inflammation for 6.0%. The mean patient age was 53.8 years, with a standard deviation of 18.5 years. A total of 55.3% of the patients were female and 44.7% were male. From 1990 to 2018, there was a continuous increase in the number of multiple tumorous lesions.

CONCLUSION

From our studies, we conclude that considering possible tumorous double lesions during surgeries and in preoperative X-ray analyses is recommended.

Co-occurrence of Functional Gonadotroph Adenoma and Lactotroph Adenoma: A Case Report and Literature Review

Background/Objective

Functional gonadotroph adenomas (FGAs) are adenomas producing active gonadotropins, follicle-stimulating hormone or luteinizing hormone. Double pituitary adenomas are 2 distinct adenomas occurring in an individual. This report aimed to present an extremely rare case of an FGA, itself an uncommon disorder, co-occurring with a lactotroph adenoma.

Case Report

A 33-year-old woman presented with menorrhagia and was found to have ovarian enlargement, large uterine leiomyomas, and bitemporal hemianopsia. Initially, the levels of follicle-stimulating hormone, luteinizing hormone, estradiol, and prolactin were 73.3 mIU/mL (midcycle peak, 2.3-20.9 mIU/L), 3.74 mIU/L (midcycle peak, 8.7-76.3 mIU/L), 1071 pg/mL (midcycle peak 38-649 pg/mL), and 402 ng/mL (2-30 ng/mL), respectively. Pituitary magnetic resonance imaging demonstrated a single sellar mass (2.0 × 2.2 cm). Two months of cabergoline did not reverse visual field deficits; therefore, transsphenoidal resection was performed. Diagnosis of 2 separate adenomas, a gonadotroph and lactotroph adenoma, was confirmed on pathology.

Discussion

In this case, gonadotropins did not suppress in response to hyperprolactinemia. Although marked hyperprolactinemia has been associated with functional and clinically silent gonadotroph adenomas in prior cases, this is the first case to confirm an FGA co-occurring with a lactotroph adenoma.

Conclusion

In patients who present with elevated gonadotropin levels despite hyperprolactinemia, we suggest considering FGA. Further research is needed to clarify whether there is underdiagnosis of lactotroph adenomas co-occurring with gonadotroph adenomas.

Neuroendocrine tumors of the pituitary gland: Modern diagnostic approach

Pituitary neuroendocrine tumors (PitNET) are neuroendocrine tumors originating from adenohypophyseal cells. Although benign, PitNETs sometimes exhibit aggressive biological behavior that was the inspiration for the change of old and traditional name "pituitary adenomas". Current standard in PitNET diagnostics, according to WHO criteria, is immunohistochemistry, with application of antibodies to adenohypophysis hormones and transcription factors TPIT (T-box family member TBX19), PIT1 (pituitary transcription factor 1) and SF-1 (steroidogenic factor-1) according to which, the line of differentiation is assessed. In the PIT1 line of differentiation there are somatotroph, lactotroph and thyrotroph tumors. Somatotroph tumors are from PIT1 lineage that produce growth hormone (GH). The WHO defines the following subtypes of somatotroph tumors: densely granulated and sparsely granulated somatotroph tumor. Lactotroph tumors are the most common neuroendocrine tumors of the pituitary gland. The transcription factors PIT1 and the estrogen receptor a (ERa) play a key role in their genesis. There are two subtypes of lactotroph tumors, densely and sparsely granulated that are differentiated by the type of prolactine (PRL) staining pattern. Thyrotroph tumors expess both PIT1 and GATA binding protein 3 (GATA3), and can show variable positivity for thyroid-stimulating hormone (TSH). Beside these three main tumor types of PIT1 lineage, there are mixed lactotroph and somatotroph tumors, mamosomatotroph tumor, acifophilic "stem cell" tumor, mature and immature plurihormonal tumor. Corticotroph tumors express transcription factor TPIT, and produce adrenocorticotrophic hormone (ACTH). They can be densely granulated and sparsely granulated. Rare subtype of corticotroph tumors, that can show aggressive biological behavior, is Crooke cell tumor. Gonadotroph tumors are of SF1 lineage of differentiation, and they produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Null-cell tumors show no distinct cell lineage, and do not express any of the transcription factors. With the use of transcription factors, these tumors are diagnosed through elimination, and their number tented to decrease.

Multiple Pituitary Adenomas: A Systematic Review

PubMed, Scopus, and Web of Science Core Collection databases were systematically searched for studies reporting synchronous double or multiple pituitary adenomas (MPA), a rare clinical condition, with a vague pathogenesis. Multiple adenomas of the pituitary gland are referred to as morphologically and/or immunocytochemically distinct tumors that are frequently small-sized and hormonally non-functional, to account for the low detection rate. There is no general agreement on how to classify MPA, various criteria, such as tumor contiguity, immunoreactivity, and clonality analysis are being used. Among the component tumors, prolactin (PRL)-immunopositive adenomas are highly prevalent, albeit mute in the majority of cases. The most frequent clinical presentation of MPA is Cushing's syndrome, given the fact that in more than 50% of reported cases at least one lesion stains for adrenocorticotrophic hormone (ACTH). Plurihormonal hyperactivity may be diagnosed in a patient with MPA when more than one tumor is clinically active (e.g., ACTH and PRL) or in cases with at least one composite tumor (e.g., GH and PRL), to complicate the clinical scenario. Specific challenges associated with MPA include high surgical failure rates, enforcing second-look surgery in certain cases, and difficult preoperative neuroradiological imaging evaluation, with an overall sensitivity of only 25% for magnetic resonance imaging to detect distinct multiple tumors. Alternatively, minor pituitary imaging abnormalities may raise suspicion, as these are not uncommon. Postoperative immunohistochemistry is mandatory and in conjunction to electron microscopy scanning and testing for transcription factors (i.e., Pit-1, T-pit, and SF-1) accurately define and classify the distinct cytodifferentiation of MPA.