Chronic expanding pituitary hematoma with calcification resulting from pituitary adenoma: illustrative case

Abstract

BACKGROUND

Pituitary apoplexy (PA) is characterized by sudden headache, vomiting, visual dysfunction, anterior lobe dysfunction, and endocrine disorder due to bleeding or infarction from a pituitary adenoma. PA occurs in approximately 0.6–10% of pituitary adenomas, more commonly in men aged 50–60 years, and more frequently in nonfunctioning and prolactin-producing pituitary adenomas. Further, asymptomatic hemorrhagic infarction is found in approximately 25% of PA.

OBSERVATIONS

A pituitary tumor with asymptomatic hemorrhage was detected on head magnetic resonance imaging (MRI). Thereafter, the patient underwent head MRI every 6 months. After 2 years, the tumor was enlarged and visual dysfunction was noticed. The patient underwent endoscopic transnasal pituitary tumor resection and was diagnosed with a chronic expanding pituitary hematoma with calcification. The histopathological findings were very similar to those of chronic encapsulated expanding hematoma (CEEH).

LESSONS

CEEH associated with pituitary adenomas gradually increases in size, causing visual dysfunction and pituitary dysfunction. In case of calcification, total removal is difficult due to adhesions. In this case, calcification developed within 2 years. A pituitary CEEH, even when showing calcification, should be operated on, as visual function can be fully recovered.

Pituitary stroke is a syndrome secondary to hemorrhage, ischemia, or hemorrhagic infarction associated with a pituitary adenoma. It is a relatively common condition that causes sudden onset of headache, nausea, visual dysfunction, and anterior segment dysfunction.

However, chronic pituitary hematoma is a rare condition in which a chronic hematoma within the pituitary adenoma gradually enlarges the hematoma, causing visual disturbance and headache. This report presents a patient with initially asymptomatic, chronic, expanding pituitary hematoma with capsular calcification, which developed visual disturbances in nearly 2 years.

Illustrative Case

A 44-year-old male with no medical history presented with the chief complaint of limb discomfort. Incidentally, head magnetic resonance imaging (MRI) indicated a tumor in the sella turcica. It was a neoplastic lesion with a maximum diameter of 37 mm from the intrasellar region to the floor of the third ventricle, bilaterally bordering the cavernous sinuses (Fig. 1). A niveau formation was observed inside the tumor, resulting in a diagnosis of pituitaryapoplexy (PA). Endocrine evaluation revealed cortisol levels of 3.58 μg/dL (normal range: 6.24–18.00), adrenocorticotropic hormone (ACTH) 18.5 pg/mL (normal range: 7.2–63.3), growth hormone (GH) 0.25 ng/mL (normal range: 0.00–2.47), free thyroxin (FT) 3 (FT3) 6.8 pg/mL (normal range: 2.1–4.2), FT4 1.46 ng/dL (normal range: 0.97–1.72), prolactin 6.4 ng/mL (normal range: 4.3–13.7), follicle-stimulating hormone (FSH) 5.3 mIU/mL (normal range: 1.5–12.4), and luteinizing hormone (LH) 2.2 mIU/mL (normal range: 1.7–8.6). Since the visual field examination revealed no abnormalities, the patient was diagnosed with asymptomatic PA and was followed up every 6 months with head MRI. Over this period, although the tumor increased in size, as there were no obvious symptoms the patient received no further intervention. Two years later, he experienced visual impairment and was referred to our hospital after being diagnosed with bilateral hemianopsia, right optic disc pallor, and deteriorated eyesight (corrected vision, 0.6). Head MRI showed that the cyst had slowly increased to a maximum diameter of 42 mm after 22 months; the internal cystic component was uniformly hypointense in T1- and T2-weighted images, with a partial niveau (Fig. 2). The tumor elevated the optic nerve and optic chiasm, extending into the cavernous sinus (Knosp grade 3). In addition, head computed tomography showed a neoplastic lesion in the suprasellar region with some calcification (Fig. 3). A blood test showed thyroid-stimulating hormone (TSH) at 7.280 μIU/mL (normal range: 0.500–5.000), FT4 at 0.40 ng/dL, cortisol at 0.84 μg/dL, and GH at 0.08 ng/mL. In addition, a GH and ACTH load test diagnosed panhypopituitarism. Based on these findings, symptomatic PA with chronic expanding hematoma was diagnosed, and an endoscopic transnasal pituitary tumor resection was performed to treat the condition.

FIG. 1.

Initial T1-weighted (A), T2-weighted (B), and enhanced T1-weighted (C) magnetic resonance (MR) images. Tumor showing high signal intensity on the T1-weighted image (A). Mirror formation inside the tumor, suggesting pituitary apoplexy (B). High signal intensity on T1-weighted images and low signal intensity on T2-weighted images (C). The tumor was in contact with the cavernous sinus.

FIG. 2.

Sagittal T2-weighted images (A–D) at several follow-up dates (3, 9, 15, and 22 months, respectively). The tumor grew slowly over the course of 22 months. There was no bleeding in the tumor. The images show a uniform isosignal within the tumor, considered to be the cystic component.

FIG. 3.

Preoperative T1-weighted (A), T2-weighted (B), and enhanced T1-weighted (C) MR images and computed tomography (CT) image (D). Tumor showing a high signal on the T1-weighted image (A). Tumor compressing the optic nerve and optic chiasm upward (B). Tumors showing contrast effects (C). Tumor with clear borders and capsule calcification (D).

Intraoperative Findings

After dissecting the nasal mucosa to the anterior wall of the sphenoid sinus, the bone was removed, and we could reach into the sphenoid sinus. A bone defect due to tumor compression was observed in the posterior wall of the sphenoid sinus. After removing more bone, the tumor was exposed through a dural incision. When tumor samples were collected for histopathology, dark serous contents leaked from within. Inside the cyst there was a deep thickened hematoma capsule with calcification; the adhesion to the surrounding area was so strong that partial detachment was impossible. Tumor components other than the cyst could be removed by aspiration. After removing the tumor extending into the cavernous sinus, gross total resection was completed.

Pathological Findings

Immunostaining results showed negative prolactin, PIT-1, and TPIT; positive SF1; and a Ki-67 index of approximately 2%, leading to a diagnosis of nonfunctioning pituitary adenoma. The capsule comprised fibrous tissue, microvascular formation, and partial beam-like bone formation (Fig. 4).

FIG. 4.

Pathological hematoxylin and eosin–stained images. A: Proliferation of round cells against a background of dendritic vessels, with no visible atypia or nuclear fission of the round cells (original magnification ×100). B: Hematoma membrane (original magnification ×4). A thick layer of collagen fibers and capsular fibrous tissue can be recognized. C: Hematoma membrane at a higher magnification (original magnification ×20). The pathological findings of the cortex showed capsular fibrous tissue and beam-like bone formation, as well as a thick layer of collagen fibers and microvascular formation.

Postoperative Course

Postoperative computed tomography showed no obvious bleeding and the head MRI in the day after surgery showed no residual tumor. After the patient complained of thirst and polyuria, a blood sample showed hypernatremia; thus, we diagnosed diabetes insipidus and started treatment with desmopressin, which allowed controlling his electrolytes and urine output. The perimetry and eyesight test showed improvement (corrected vision, 1.5). On the 15th day after surgery, he was discharged.

Discussion

Observations

Pituitary strokes associated with pituitary adenomas are common, with a frequency of 2–12%.^1–3 However, unlike in acute-onset PA, the patient experienced a 2-year course of visual deterioration and panhypopituitarism due to chronic hematoma enlargement. To our knowledge, only 6 cases of a similar condition have been reported in the past. Sugawara et al. found that the histopathological findings were very similar to those of chronic encapsulated expanding hematoma (CEEH).^4,5 Intrasellar cystic lesions with lateral extension above Knosp grade 1 are likely CEEH associated with pituitary adenomas. Characteristic histopathological findings include the following: (1) thick fibrous tissue between the hematoma and adenoma, (2) a thin fibrous layer between the normal pituitary and the adenoma, (3) a thick collagenous fibrous layer and hemosiderin deposits in the surrounding area, (4) presence of neovascular endothelial cells, (5) presence of a large amount of collagenous tissue in the granulation tissue, and (6) presence of CD34-positive neovascular endothelial cells. The findings of this case are consistent with those above. The underlying mechanism is supposedly similar to that of a chronic subdural hematoma, and the pathophysiology resulting in hematoma enlargement, a contemplative cycle of hemorrhage, coagulation, fibrinolysis, and rebleeding from the neovascular outer membrane. In contrast to acute-onset PA, this patient showed visual deterioration due to slow cystic enlargement, and a serous dark reservoir was observed within the cyst. Combined pathological examination resulted in diagnosis of CEEH after pituitary stroke associated with pituitary adenoma. In this case, calcification was observed in the capsule, suggesting vitreous-like degeneration of the capsule over time, similar to the capsule calcification observed in chronic subdural hematoma.^6,7 Chronic hematoma formation due to CEEH should have been considered a differential diagnosis based on preoperative computed tomography imaging. To the best of our knowledge, this is the first report of a case of CEEH in the pituitary region diagnosed as asymptomatic PA, in which cyst wall calcification appeared after a long follow-up period.

Although CEEH with calcification may be accompanied by adhesions to normal tissue, even if the capsule remains, visual function can be improved by tumor and cyst removal; therefore, aggressive therapeutic intervention is recommended.

Lessons

In this report, we describe a case of chronic hematoma associated with a pituitary adenoma that enlarged over approximately 2 years. Despite previous reports of rebleeding after PA, in this patient, slow hematoma growth led to visual deterioration and hypopituitarism.

More frequent monitoring of hematoma expansion, such as MRI every 3 months, is needed, and surgery should be performed if there is a tendency for hematoma expansion even in the absence of visual deterioration. In case of suspected CEEH associated with a pituitary adenoma, surgery should be performed, since calcification suggests a long-term course, as it is expected to improve visual function.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Yagi, Takagi, Tsuji, Wanibuchi. Acquisition of data: Takagi, Tsuji, Nonoguchi. Analysis and interpretation of data: Takagi, Takami. Drafting of the article: Takagi. Critically revising the article: Takagi, Ikeda, Takami. Reviewed submitted version of the manuscript: Takagi, Ikeda, Kawabata. Approved the final version of the manuscript on behalf of all authors: Yagi. Statistical analysis: Takagi. Administrative/technical/material support: Takagi, Kanemitsu, Nonoguchi. Study supervision: Takagi, Furuse, Kawabata.