A novel hook-shaped enhancement on contrast-enhanced sagittal magnetic resonance image in acute Sheehan's syndrome: a case report

Acute Sheehan's Syndrome Presenting with Hyponatremia Followed by a Spontaneous Pregnancy

BACKGROUND

Acute Sheehan's syndrome is rare, as well as hyponatremia as its initial manifestation. In addition, spontaneous pregnancy in patients after Sheehan's syndrome is unusual. To our knowledge, no cases of spontaneous pregnancy after acute Sheehan's syndrome have been reported. We describe a case of Sheehan's syndrome that presented with acute hyponatremia and a spontaneous pregnancy.

CASE

A 34-year-old female developed blood loss during delivery, which required a blood transfusion. On day seven postpartum, she presented with headaches, lethargy, and difficulty in breastfeeding. The workup showed hyponatremia (118 mEq/l), secondary hypothyroidism, and low prolactin levels. Magnetic resonance imaging showed pituitary necrosis. She was treated with NaCl, hydrocortisone (cortisol results were not available), and levothyroxine. Laboratory tests six weeks after discharge showed low IGF-1 and 8 AM cortisol and normal FT4, LH, FSH, and PRL levels. She was able to partially breastfeed until 4 months postpartum. Regular menstrual cycles started three months later. She became spontaneously pregnant one year later.

CONCLUSION

Acute Sheehan's syndrome should be considered in the evaluation of postpartum patients with suggestive symptoms. Physicians should be aware that hyponatremia could be an initial manifestation of Sheehan's syndrome, which requires a high index of suspicion for diagnosis. Spontaneous pregnancy can occur after acute Sheehan's syndrome.

A case of acute Sheehan's syndrome and literature review: a rare but life-threatening complication of postpartum hemorrhage

Background

Sheehan’s syndrome occurs because of severe postpartum hemorrhage causing ischemic pituitary necrosis. Sheehan’s syndrome is a well-known condition that is generally diagnosed several years postpartum. However, acute Sheehan’s syndrome is rare, and clinicians have little exposure to it. It can be life-threatening. There have been no reviews of acute Sheehan’s syndrome and no reports of successful pregnancies after acute Sheehan’s syndrome. We present such a case, and to understand this rare condition, we have reviewed and discussed the literature pertaining to it. An electronic search for acute Sheehan’s syndrome in the literature from January 1990 and May 2014 was performed.

Case presentation

A 27-year-old woman had massive postpartum hemorrhage (approximately 5000 mL) at her first delivery due to atonic bleeding. She was transfused and treated with uterine embolization, which successfully stopped the bleeding. The postpartum period was uncomplicated through day 7 following the hemorrhage. However, on day 8, the patient had sudden onset of seizures and subsequently became comatose. Laboratory results revealed hypothyroidism, hypoglycemia, hypoprolactinemia, and adrenal insufficiency. Thus, the patient was diagnosed with acute Sheehan’s syndrome. Following treatment with thyroxine and hydrocortisone, her condition improved, and she was discharged on day 24.

Her next pregnancy was established 2 years after her first delivery. She required induction of ovulation for the next conception. The pregnancy, delivery, and postpartum period were uneventful. An electronic search of the literature yielded 21 cases of acute Sheehan’s syndrome. Presenting signs varied, including adrenal insufficiency (12 cases), diabetes insipidus (4 cases), hypothyroidism (2 cases), and panhypopituitarism (3 cases), with a median time of presentation after delivery for each of those conditions being 7.9, 4, 18, and 9 days, respectively. Serial changes in magnetic resonance imaging were reported in some cases of acute Sheehan’s syndrome.

Conclusion

Clinicians should be aware of the risk of acute Sheehan’s syndrome after a massive postpartum hemorrhage in order to diagnose it accurately and treat it promptly.

Sheehan syndrome

Sheehan syndrome or postpartum hypopituitarism is a condition characterized by hypopituitarism due to necrosis of the pituitary gland. The initial insult is caused by massive postpartum haemorrhage (PPH), leading to impaired blood supply to the pituitary gland, which has become enlarged during pregnancy. Small sella turcica size, vasospasms (caused by PPH) and/or thrombosis (associated with pregnancy or coagulation disorders) are predisposing factors; autoimmunity might be involved in the progressive worsening of pituitary functions. Symptoms are caused by a decrease or absence of one or more of the pituitary hormones, and vary, among others, from failure to lactate and nonspecific symptoms (such as fatigue) to severe adrenal crisis. In accordance with the location of hormone-secreting cells relative to the vasculature, the secretion of growth hormone and prolactin is most commonly affected, followed by follicle-stimulating hormone and luteinizing hormone; severe necrosis of the pituitary gland also affects the secretion of thyroid-stimulating hormone and adrenocorticotropic hormone. Symptoms usually become evident years after delivery, but can, in rare cases, develop acutely. The incidence of Sheehan syndrome depends, to a large extent, on the occurrence and management of PPH. Sheehan syndrome is an important cause of hypopituitarism in developing countries, but has become rare in developed countries. Diagnosis is based on clinical manifestations combined with a history of severe PPH; hormone levels and/or stimulation tests can confirm clinical suspicion. Hormone replacement therapy is the only available management option so far.

Visualization of the normal pituitary gland during the endoscopic endonasal removal of pituitary adenoma by narrow band imaging

BACKGROUND

Narrow band imaging (NBI) is an endoscopic technology that enhances the visualization of the superficial and submucosal vasculature. The aim of the present study was to evaluate the feasibility of NBI in visualizing the normal pituitary gland during the endoscopic endonasal removal of pituitary adenoma.

METHODS

A total of 25 patients with pituitary adenoma underwent endoscopic endonasal transsphenoidal surgery using a rigid endoscope with conventional imaging. The NBI of the surgical field was conducted under air and/or continuous irrigation of artificial cerebrospinal fluid using a flexible videoscope before and/or after the gross removal of the tumor.

RESULTS

The capillaries of the normal pituitary gland had a characteristic appearance that could be confirmed in 16 cases. In contrast, the adenomas exhibited no characteristic vascular enhancement under NBI. The reasons why NBI failed to visualize the pituitary gland included the presence of a blood clot or a certain amount of tumor obscuring the normal pituitary gland and difficulty in steering the videoscope within the sella to approach the assumed site of the residual pituitary gland.

CONCLUSIONS

NBI observation during the endoscopic endonasal removal of pituitary adenoma may be useful for visualizing the normal pituitary gland after the gross removal of the tumor. The absence of a typical vascular pattern suggests the presence of a residual tumor, which may justify further exploration in cases where gross total removal is considered necessary.