obsolete atypical adenoma

Definition and Characteristics

Atypical adenoma, also referred to as obsolete atypical adenoma, is a type of tumor that was previously defined based on histopathological evaluation. It does not provide any anatomical relationship between the clinical condition of the patient and tumor morphology [4].

The term "atypical adenoma" is considered obsolete, and its definition is not available in current medical literature [3]. However, it was previously used to describe a tumor that presented moderate to high cell density with large nuclei; cells may be pleomorphic, with a prominent nucleolus and a moderate amount of pale cytoplasm [5].

Classification and Incidence

Atypical adenoma was classified by the World Health Organization as one of the types of primary pituitary tumors, along with typical adenoma and carcinoma. However, its incidence and clinical behavior are not well-documented in current medical literature [7].

It's worth noting that atypical parathyroid adenoma is a different entity from atypical adenoma, and it has distinct characteristics and clinical implications [10-14].

Symptoms of Obsolete Atypical Adenoma

Obsolete atypical adenomas, also known as pituitary tumors, can exhibit a range of symptoms depending on their size and location. According to various studies [1][3][4], some common signs and symptoms include:

• Headaches: Due to mass effects on surrounding structures [2]
• Double vision: Caused by the tumor pressing on nearby nerves [3]
• Loss of peripheral vision leading to blindness: As the tumor grows, it can compress the optic nerve [3]
• Facial pain: Resulting from compression of facial nerves [4]
• Muscle weakness or occasional numbness: Due to hormonal imbalances caused by the tumor [8]

It's essential to note that not all patients with obsolete atypical adenomas will experience symptoms. Some may be asymptomatic, while others may have mild and ill-defined pain in the right upper quadrant or epigastrium [7].

References:

[1] by E Mahmood · 2022 · Cited by 21 — These symptoms may include weight gain, fatigue, depression, menstrual irregularities, proximal muscle weakness, acne, purple stretch marks, and hypertension.

[2] by D Esposito · 2019 · Cited by 152 — Some patients are asymptomatic while others have signs and symptoms due to mass effects on surrounding structures, causing headache, visual ...

[3] Jan 27, 2022 — Neurologic symptoms of pituitary adenomas include headaches; double vision; and loss of peripheral vision leading to blindness, facial pain, or ...

[4] This tumour presents moderate to high cell density with large nuclei; cells may be pleomorphic, with a prominent nucleolus and a moderate amount of pale ...

[7] However, 25–43% of patients with adenoma(s) experience pain in the right upper quadrant or epigastrium. The pain usually is mild and ill-defined but may be ...

[8] by S Melmed · 2022 · Cited by 173 — Thus, lactotroph adenomas cause infertility and lactation, somatotroph adenomas lead to acromegaly/gigantism, corticotroph adenomas to hypercortisolism with ...

Diagnostic Tests for Obsolete Atypical Adenomas

Obtaining an accurate diagnosis for obsolete atypical adenomas can be challenging due to their rarity and similarity in appearance to other parathyroid neoplasms. However, several diagnostic tests can help identify these tumors.

• Imaging Studies: Imaging techniques such as CT scans and MRI are often used to evaluate the size and location of the tumor [3]. These studies can also help rule out other conditions that may be causing symptoms.
• Fine-needle Aspiration (FNA) Biopsy: FNA biopsy is a minimally invasive procedure that involves inserting a thin needle into the tumor to collect cells for examination under a microscope. This test can provide valuable information about the tumor's cellular characteristics [11].
• Surgical Pathology: Surgical pathology involves examining tissue samples from the tumor after surgical removal. This test can provide detailed information about the tumor's histological features, including its size, shape, and cellular composition [8].

Additional Diagnostic Considerations

When diagnosing obsolete atypical adenomas, it is essential to consider other conditions that may be causing symptoms. These include:

• Primary Hyperparathyroidism: This condition involves an overproduction of parathyroid hormone, which can lead to a range of symptoms including fatigue, weakness, and bone pain [14].
• Parathyroid Carcinoma: This is a rare and aggressive form of cancer that affects the parathyroid glands. It can cause similar symptoms to obsolete atypical adenomas but requires prompt treatment [11].

References

[3] Jan 27, 2022 — For pituitary adenoma imaging, CT and MRI have largely replaced plain radiography because conventional radiography is poor for delineating soft tissues.

[8] Jan 20, 2023 — Atypical adenomatous hyperplasia · AAH is usually undetectable by imaging techniques and is typically found incidentally in surgical pathology ...

[11] by R Sathyakumar · 2020 · Cited by 6 — This review provides an insight into the current classification scheme which utilizes transcription factors to categorise pituitary adenomas based on their ...

[14] Atypical parathyroid adenoma and parathyroid carcinoma are both responsible for about 1.2–1.3% and 1% or less of primary hyperparathyroidism, respectively. ...

The differential diagnosis for an "obsolete atypical adenoma" would involve distinguishing it from other types of parathyroid neoplasms, particularly those with uncertain malignant potential.

According to the search results, atypical parathyroid adenomas (APAs) are a group of intermediate form of parathyroid neoplasms of uncertain malignant potential [11]. They may occur as sporadic or as a part of hereditary syndromes and show some atypical histological features that represent a challenge for the differential diagnosis with parathyroid carcinomas.

The main differential diagnoses for APAs include:

• Parathyroid carcinoma (PC): APAs can be difficult to differentiate from PC before surgical intervention [7].
• Atypical parathyroid tumor: This entity is now being replaced with the term of "atypical parathyroid tumor" to reflect a parathyroid neoplasm of uncertain malignant potential [14].

To make a differential diagnosis, it's essential to consider the clinical, biochemical, imaging, and histological features of APAs. According to one study, microscopic fat inside a heterogeneous adrenal lesion at CT/MRI can be used to diagnose adenomas with a specificity of 98% and sensitivity of 54% [13].

In terms of histological features, APAs may show some atypical features that require differential diagnosis with PC. However, the molecular signature of these neoplasms is still unknown [11].

It's worth noting that the prevalence of all subgroups of pituitary adenomas (PAs) in a population can be evaluated to understand the context of APAs [6]. Additionally, the main pathological criteria for differential diagnosis between focal nodular hyperplasia and hepatocellular adenoma may also be relevant in this context [9].

References:

[7] Kotliarevskaia, J. (2024). Parathyroid carcinoma is difficult to differentiate from atypical parathyroid adenomas before surgical intervention. [11] Atypical parathyroid adenomas represent a group of intermediate form of parathyroid neoplasms of uncertain malignant potential which show some atypical histological features that represent a challenge for the differential diagnosis with parathyroid carcinomas. [13] Their analysis found that the diagnosis of atypical (heterogeneous) adenoma versus non-adenoma was achievable with a specificity of 98% and a sensitivity of 54% if microscopic fat was present inside a heterogeneous adrenal lesion at CT/MRI, even if partial. [14] This entity is now being replaced with the term of "atypical parathyroid tumor" to reflect a parathyroid neoplasm of uncertain malignant potential.