Lymphocytic hypophysitis: An underrated disease
Amruta Ashok Patil1, Purwa Patil2, Vaishali Walke3
1 Department of Pathology, Bharati Vidyapeeth Deemed University Medical College, Sangli, India
2 Department of Pathology, Grant Medical College, Mumbai, Maharashtra, India
3 Department of Pathology, Indira Gandhi Government Medical College, Nagpur, Maharashtra, India
Correspondence Address:
Amruta Ashok Patil
Department of Pathology, Bharati Vidyapeeth Deemed University Medical College, Sangli, Maharashtra
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/jmh.jmh_32_21
Lymphocytic hypophysitis (LYH) is a rare inflammatory disease in which lymphoplasmacytic infiltration of the pituitary gland can potentially lead to panhypopituitarism. This entity was first recognized in 1962 by Goudie and Pinkerton. We report the case of a 36-year-old nonpregnant female operated for a presumed nonsecreting pituitary adenoma. On intraoperative squash cytology and histology of excision biopsy confirmed the diagnosis of LYH. Review of the literature shows that most reported cases have occurred in women during pregnancy or during postpartum period. Many were accurately diagnosed only after biopsy or at necropsy. It is suspected to be an autoimmune endocrinopathy as concomitant lymphocytic infiltration of the thyroid and pituitary glands has been noted and antipituitary antibodies have been found in some instances. Clinically and radiologically, LYH may mimic a nonsecretory pituitary adenoma. Intraoperative diagnosis may prevent unnecessary excision of potentially functioning pituitary.
Keywords: Lymphocytic hypophysitis, pituitary adenoma, squash
Lymphocytic hypophysitis (LYH) is an inflammatory lesion of the pituitary gland. It can be misdiagnosed for tumors in the sellar or parasellar region because of its clinical and radiological features.[1] It is characterized by infiltration of the pituitary gland by lymphocytes, plasma cells, and macrophages. It has a female preponderance, especially during pregnancy or postpartum period.[2] It is rarely seen in nonpregnant females and in men. Some authors have suggested autoimmune or viral etiology.[3]
Case ReportA 36-year-old woman presented with 3 months history of headache, bilaterally diminished vision, and polyuria. She had no significant past medical or obstetric history. She had no personal or family history of autoimmune diseases. The physical examination was normal. Visual field perimetry showed right vision as 6/12 and left as 6/6 with bitemporal field defect. The computed tomography scan showed a mass lesion in the suprasellar region with widening and without erosion of sellar and ethmoid process, suggesting the diagnosis of pituitary adenoma. Bilateral cavernous sinuses and internal carotid arteries were free. Magnetic resonance (MR) of the pituitary gland supported the diagnosis of pituitary adenoma measuring 12.5 mm × 10.4 mm × 17.8 mm with suprasellar extension and minimally elevated chiasma. The infundibular stalk was normal. There was postcontrast homogenous enhancement in the mass lesion [Figure 1].
Figure 1: Magnetic resonance imaging (MRI) showing lobulated mass lesion in the sellar-suprasellar region, Inset - MRI contrast enhancement of the mass lesionThe baseline hormone levels were normal except for hypothyroidism.
By endoscopic transnasal transsphenoidal approach, biopsy of the lesion was done. The lesion was gray white, soft to firm, not easily suckable, and moderately vascular. Squash cytology preparation showed pituitary gland parenchyma with extensive inflammation and fibrosis, hence, diagnosis of inflammatory lesion was offered [Figure 2]. Histopathological examination of the lesion showed pituitary gland with marked fibrosis of the interstitium and dense infiltrate of lymphocytes, few plasma cells, and macrophages. Similar cells were also seen infiltrating acini at places of lymphoid aggregates with germinal centers [Figure 3]. Immunohistochemistry supported inflammatory pathology with strongly positive leukocyte common antigen in mononuclear cell infiltrate. Special stains for microorganisms, including periodic acid-Schiff and methionine silver were all negative. On the basis of these findings, the diagnosis of LYH was made.
Figure 2: Squash cytology showing inflammatory infiltrate with few entangled epithelial cells (H and E, ×10)Figure 3: Pituitary glandular epithelium with infiltration by lymphocytes, few plasma cells, and macrophages (H and E, ×10) Inset - Higher power of the same (H and E, ×40)During follow-up, she has developed galactorrhea with increased prolactin levels, managed by high dose bromocriptine (20 mg/day). Conjugated estrogen (0.625 mg/day), medroxyprogesterone acetate (5 mg/day), desmopressin acetate (10 mU/day) and thyroxin (l-T4) (100 mg/day) was started. Six months after the replacement therapy, she was doing well without any signs or symptoms of endocrine failure. The dose of bromocriptine SRO was lowered gradually (until 5 mg/day), and she was invited to regular clinical follow-up.
One year after surgery, she was asymptomatic with no residual lesion on MR imaging (MRI) and normal endocrine functions.
DiscussionLYH is a rare inflammatory disease of the anterior pituitary gland, first described by Goudie and Pinkerton in 1962. Since then, more than 120 cases have been reported.[1]
Primary LYH is confined to the pituitary gland with no identifiable etiologic association. Histologically, it is of LYH, granulomatous hypophysitis, and xanthomatous hypophysitis type. Inflammation triggered by definite etiologic infective agent or known systemic disease.[3]
LYH mainly affects women during pregnancy or in postpartum period with symptoms related to features of mass lesion at pituitary and hypopituitarism. The diagnosis depends on the clinical suspicion and can only be clearly established by histological examination. There are no definite biochemicals or serological markers although the role of antipituitary antibodies is under study.[2]
Panhypopituitarism due to lymphoplasmacytic pituitary infiltration was described by Rapp and Pashkis in 1953.[4] The inflammation is generally confined to the anterior pituitary, but the involvement of posterior pituitary presenting as diabetes insipidus can be seen.[5]
MR shows uniform sellar floor depression with extrasellar symmetrical pituitary enlargement, displacing the optic chiasma. Gadolinium enhancement can show dural tail.
The mean age at diagnosis is 34.5 years for women and 44.7 years for men. There is a female predilection of about 8.5:1 mainly affecting women in peripartum period. However, it has also been described in postmenopausal and prepubertal age groups.[6]
Our patient was neither pregnant nor postpartum. The occurrence of LYH without associated pregnancy could be more frequent than previously considered.
Mass effect due to extrasellar pituitary enlargement may cause optic chiasma compression causing headache, visual field impairment, and diplopia. The enlarged gland may produce mass effect in the initial stages and symptoms get relieved in a later stage due to fibrosis and shrinkage.
Diagnosis of pituitary adenoma is usually thought with clinical and radiological features but definitive diagnosis is made through histopathological examination. Some authors consider LYH and pituitary adenoma as different expressions of the same disease and distinguished only with histological examination.[3] Histopathological examination reveals atrophic pituitary acini with lymphoplasmacytic infiltrate forming lymphoid aggregates and areas of reactive fibrosis.[7]
A spontaneous remission can occur in some patients. Medical treatment in the form of immunosuppressive, hormone replacement, antiprolactinemic drugs, and/or neurosurgical treatment (decompression) are needed.[3]
Presentation of subclinical hypothyroidism and initial normal prolactin levels in this unusual case provides additional insights into the presentation of LYH. Addition of the deficient hormones and corticosteroid therapy has been effective in some patients. Transsphenoidal surgery is both diagnostic and therapeutic. However, surgical intervention may result in further deterioration of pituitary gland function if all the potentially viable pituitary tissue is resected. It has been suggested that in the cases of suspected hypophysitis, a frozen section should be performed to confirm the diagnosis and aggressive resection of potentially viable pituitary tissue is avoided.[8]
ConclusionLYH is a rare disorder of the pituitary gland generally affecting women in postpartum period but unusually can present in nonpregnant nonpostpartum period. The clinical presentation may mimic the pituitary adenoma but intraoperative diagnosis of inflammatory lesion may prevent unnecessary excision of potentially functioning pituitary.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
Comments (0)