AVP Deficiency as the Initial Manifestation of Multisystem Langerhans Cell Histiocytosis: A Diagnostic Odyssey
https://doi.org/10.15605/jafes.041.S1
- Author:
Yuvaranee Samanaseh
1
;
Vanusha Devaraja
1
;
Goh Qing Ci
1
;
Patricia Lee Siow Ping
1
Author Information
1. Hospital Melaka
- Publication Type:Journal Article
- MeSH:
Histiocytosis, Langerhans-Cell
- From:
Journal of the ASEAN Federation of Endocrine Societies
2026;41(S1):92-
- CountryPhilippines
- Language:English
-
Abstract:
Introduction:Arginine vasopressin (AVP) deficiency is an uncommon
but important presentation of infiltrative hypothalamic–
pituitary disorders. In adults, isolated AVP deficiency with
pituitary stalk thickening is diagnostically challenging,
especially in the absence of systemic disease. Langerhans
cell histiocytosis (LCH) is a rare cause and may precede
systemic involvement by several years.
Case:We report a 42-year-old male who presented in 2017 with
polyuria and polydipsia, with urine output of up to 10 L/
day. AVP deficiency was confirmed by the water deprivation
test, and desmopressin was initiated. Initial pituitary
magnetic resonance imaging (MRI) was normal, baseline
anterior pituitary hormonal evaluation was unremarkable, and contrast-enhanced computed tomography (CECT) of
the thorax and abdomen showed no abnormalities.
Repeat pituitary MRI 1 year later demonstrated loss of
the posterior pituitary bright spot with pituitary stalk
thickening. In the absence of systemic involvement, a
presumptive diagnosis of lymphocytic hypophysitis was
made, and pituitary biopsy was deferred due to the high
procedural risk.
Serial pituitary MRIs over the following years showed
persistent infundibular thickening and continued absence
of the posterior pituitary bright spot, without interval
progression or development of additional hormonal
deficiencies. The patient remained clinically stable until
June 2024, when new-onset left hip pain prompted MRI,
revealing a heterogeneous mass involving the femoral
neck and intertrochanteric region with a pathological
fracture. Histopathological examination following wide
resection confirmed LCH, with negative BRAF V600
mutation. Postoperative PET scan revealed a multisystem
disease involving the skeleton, lymph nodes, spine, and
gastrointestinal tract, with no bone marrow involvement.
He subsequently completed six cycles of intravenous
methotrexate and cytarabine.
Conclusion:Adult-onset AVP deficiency may be the earliest
manifestation of occult multisystem Langerhans cell
histiocytosis. This case highlights the importance of longterm follow-up and reconsideration of the initial diagnosis
when new systemic features emerge.
- Full text:2026080415083608345EP_A131.pdf
