Typing of inflammatory lesions of the pituitary

Inflammatory and Infectious Disorders in Endocrine Pathology

A variety of inflammatory conditions may directly involve the endocrine glands, leading to endocrine dysfunction that can cause severe consequences on patients' health, if left untreated. Inflammation of the endocrine system may be caused by either infectious agents or other mechanisms, including autoimmune and other immune-mediated processes. Not infrequently, inflammatory and infectious diseases may appear as tumor-like lesions of endocrine organs and simulate neoplastic processes. These diseases may be clinically under-recognized and not infrequently the diagnosis is suggested on pathological samples. Thus, the pathologist should be aware of the basic principles of their pathogenesis, as well as of their morphological features, clinicopathological correlates, and differential diagnosis. Interestingly, several systemic inflammatory conditions show a peculiar tropism to the endocrine system as a whole. In turn, organ-specific inflammatory disorders are observed in endocrine glands. This review will focus on the morphological aspects and clinicopathological features of infectious diseases, autoimmune disorders, drug-induced inflammatory reactions, IgG4-related disease, and other inflammatory disorders involving the endocrine system. A mixed entity-based and organ-based approach will be used, with the aim to provide the practicing pathologist with a comprehensive and practical guide to the diagnosis of infectious and inflammatory disorders of the endocrine system.

Characteristics of inflammatory and infectious diseases of the pituitary gland in patients undergoing transsphenoidal surgery

PURPOSE

Inflammatory and infectious diseases of the pituitary gland (IIPD) are rare lesions often misdiagnosed preoperatively. Immediate surgery is indicated especially in cases of neurological impairment. However, (chronic) inflammatory processes can mimic other pituitary tumors, such as adenomas, and data on the preoperative diagnostic criteria for IIPD are sparse.

METHODS

We retrospectively reviewed medical records of 1317 patients who underwent transsphenoidal surgery at our institution between March 2003 and January 2023. A total of 26 cases of histologically confirmed IIPD were identified. Patient records, laboratory parameters, and postoperative course were analyzed and compared with an age, sex, and tumor volume-matched control group of nonfunctioning pituitary adenomas.

RESULTS

Pathology confirmed septic infection in ten cases, most commonly caused by bacteria (3/10) and fungi (2/10). In the aseptic group, lymphocytic hypophysitis (8/26) and granulomatous inflammation (3/26) were most frequently observed. Patients with IIPD commonly presented with endocrine and/or neurological dysfunction. No surgical mortality occurred. Preoperative radiographic findings (cystic/solid tumor mass, contrast enhancement) did not significantly differ between IIPD and adenomas. At follow-up, 13 patients required permanent hormone substitution.

CONCLUSION

In conclusion, correct preoperative diagnosis of IIPD remains challenging, as neither radiographic findings nor preoperative laboratory workup unequivocally identify these lesions. Surgical treatment facilitates decompression of supra- and parasellar structures. Furthermore, this low-morbidity procedure enables the identification of pathogens or inflammatory diseases requiring targeted medical treatment, which is crucial for these patients. Establishing a correct diagnosis through surgery and histopathological confirmation thus remains of utmost importance.

Executive summary of the consensus document on hypophysitis of the Neuroendocrinology Area of Knowledge of the Spanish Society of Endocrinology and Nutrition

The term hypophysitis is used to designate a heterogeneous group of pituitary conditions characterized by the presence of inflammatory infiltration of the adenohypophysis, neurohypophysis, or both. Although hypophysitis are rare disorders, the most common in clinical practice is lymphocytic hypophysitis, a primary hypophysitis characterized by lymphocytic infiltration, which predominantly affects women. Other forms of primary hypophysitis are associated with different autoimmune diseases. Hypophysitis can also be secondary to other disorders such as sellar and parasellar diseases, systemic diseases, paraneoplastic syndromes, infections, and drugs, including immune checkpoint inhibitors. The diagnostic evaluation should always include pituitary function tests and other analytical tests based on the suspected diagnosis. Pituitary magnetic resonance imaging is the investigation of choice for the morphological assessment of hypophysitis. Glucocorticoids are the mainstay of treatment for most symptomatic hypophysitis.

IgG4-related hypophysitis: A monocentric experience from North India

Background

Immunoglobulin (Ig)G4-related disease is a systemic fibroinflammatory disease characterized by dense infiltration of IgG4-positive plasma cells in the affected tissue(s) with or without elevated plasma levels of IgG4. Hypophysitis itself is a very rare disease with reported prevalence in the operative specimens are around 0.2-0.88%. IgG4-related hypophysitis (IgG4-RH) may account for a substantial percentage of cases previously regarded as idiopathic hypophysitis.

Methods

This study is a registry-based, retrospective, and cohort study from a tertiary care hospital in North India. The medical records and clinical data of biopsy-proven and suspected IgG4-RH patients registered were retrospectively analyzed. Treatment outcome of cases was also explored during this analysis.

Results

Two thousand and six sellar area space-occupying lesions have been operated-on since 2006, among them only four patients had IgG4-RH on histopathological specimen. One case was diagnosed on clinical suspicion. Mean age of the patients was 31.8 ± 6.32 years. Most frequent presenting complaint was headaches. Extracranial manifestations were present in four patients. The most common pituitary dysfunction was cortisol deficiency. 18 F-fluorodeoxyglucose positron emission tomography (18F FDG PET) was helpful in three cases for diagnosis of hypophysitis and other organ involvement. Classical histological findings with storiform fibrosis, obliterative phlebitis seen in two cases, and IgG4-positive plasma cell infiltration were positive in four cases. Surgery was the primary modality of treatment in all four cases. Only one patient received steroids as a primary therapeutic modality.

Conclusion

IgG4-RH is rare. High index of suspicion is required to diagnosis the case precisely. FDG PET is helpful in diagnosing hypophysitis and extrapituitary lesions.

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.

Autoimmune disease of head and neck, imaging, and clinical review

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

Suppression of Pituitary Hormone Genes in Subjects Who Died From COVID-19 Independently of Virus Detection in the Gland

CONTEXT

Involvement of the pituitary gland in SARS-CoV-2 infection has been clinically suggested by pituitary hormone deficiency in severe COVID-19 cases, by altered serum adrenocorticotropic hormone (ACTH) levels in hospitalized patients, and by cases of pituitary apoplexy. However, the direct viral infection of the gland has not been investigated.

OBJECTIVE

To evaluate whether the SARS-CoV-2 genome and antigens could be present in pituitary glands of lethal cases of COVID-19, and to assess possible changes in the expression of immune-related and pituitary-specific genes.

METHODS

SARS-CoV-2 genome and antigens were searched in the pituitary gland of 23 patients who died from COVID-19 and, as controls, in 12 subjects who died from trauma or sudden cardiac death. Real-time reverse transcription polymerase chain reaction (PCR), in situ hybridization, immunohistochemistry, and transmission electron microscopy were utilized. Levels of mRNA transcripts of immune-related and pituitary-specific genes were measured by the nCounter assay.

RESULTS

The SARS-CoV-2 genome and antigens were detected in 14/23 (61%) pituitary glands of the COVID-19 group, not in controls. In SARS-CoV-2-positive pituitaries, the viral genome was consistently detected by PCR in the adeno- and the neurohypophysis. Immunohistochemistry, in situ hybridization, and transmission electron microscopy confirmed the presence of SARS-CoV-2 in the pituitary. Activation of type I interferon signaling and enhanced levels of neutrophil and cytotoxic cell scores were found in virus-positive glands. mRNA transcripts of pituitary hormones and pituitary developmental/regulatory genes were suppressed in all COVID-19 cases irrespective of virus positivity.

CONCLUSION

Our study supports the tropism of SARS-CoV-2 for human pituitary and encourages exploration of pituitary dysfunction after COVID-19.

IgG4-related hypophysitis: a retrospective cohort study

Purpose

IgG4-related hypophysitis (IgG4-RH) is a rare chronic inflammatory condition of the pituitary gland. This study reports the presentation, management and outcomes for patients with histologically proven IgG4-related hypophysitis.

Methods

A prospectively maintained electronic database was searched over a 14-year period from 1 January 2007 to 31 December 2020 at a single academic centre to identify all patients with a histological diagnosis of IgG4-RH. A retrospective case note review from electronic health records was conducted for each case to extract data on their presentation, management and outcomes.

Results

A total of 8 patients (5 male) with a median age of 51 years were identified. The most common presenting symptoms were headache (4/8; 50%), fatigue (3/8; 37.5%) and visual impairment (2/8; 25%). Three patients were initially treated with high-dose steroids aiming for reduction of the pituitary mass. However, ultimately all patients underwent transsphenoidal surgery. Post-operative changes included radiological reduction in pituitary mass in all patients that had imaging (7/7; 100%), improvement in vision (1/2; 50%), residual thick pituitary stalk (5/7; 71.4%), persistent anterior hypopituitarism (4/8; 50%) and panhypopopituitarism including diabetes insipidus (3/8; 37.5%).

Conclusions

IgG4-RH is an increasingly recognised entity presenting with a variety of symptoms and signs. Clinical presentation is similar to other forms of hypophysitis. It is therefore important to consider IgG4-RH as a differential and to have a low threshold for pituitary biopsy, the diagnostic gold standard. The diagnosis of IgG4-RH will guide decisions for additional workup for IgG4-related disease, multi-disciplinary team involvement and follow-up.

Case of an atypical pituitary abscess

A pituitary abscess is a rare intrasellar infection. Correct identification can be challenging preoperatively given its non-specific symptoms and imaging findings. We report a case of a young woman presenting with secondary amenorrhea, visual field deficits and a 2.6 cm pituitary lesion diagnosed to be a craniopharyngioma. A concomitant unexpected pituitary abscess was diagnosed intraoperatively without associated meningeal symptoms.