A case report of syndrome of inappropriate antidiuretic hormone secretion with Castleman's disease and lymphoma

Abstract

Background: Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common cause of hyponatremia in hospitalized patients and is often described in patients with small-cell carcinoma of the lung. In this report, we described both Castleman's disease and lymphoma coexisting in one patient with SIADH.

Case presentation: A 70-year-old Chinese woman with a history of diabetes mellitus and insulin therapy had severe hyponatremia and gastrointestinal symptoms. Through a series of examinations, common causes such as pulmonary carcinoma were excluded. An abdominal mass was detected by computed tomography. Although the peripheral lymph node biopsy showed the pathological result as Castleman's disease, the pathology of the abdominal lymph node revealed diffuse large B-cell lymphoma. After chemotherapy, the hyponatremia was treated during a period of follow-up.

Conclusion: This patient presented with the rare clinical condition of inappropriate antidiuretic hormone secretion alongside Castleman's disease and lymphoma. Asymptomatic hyponatremia may persist for some time suggesting that clinical physicians should pay attention to the mild cases of hyponatremia. We also hypothesized that Castleman's disease is a condition of pre-lymphoma with both having the ability to cause SIADH. The possibility of lymphoma as well as Castleman's disease triggering the development of SIADH should also be taken into consideration for conducting recurrent biopsies.

Figure 1

CT scan of abdomen showing a mass. Axial contrast-enhanced CT image shows a large lobulated irregular mass with inhomogenous enhancement that is encasing and anteriorly displacing the abdominal aorta.

Figure 2

The pathological exam suggests Castleman’s disease. The gross examination of the inguenal lymph node biopsy specimen shows a fairly well-encapsulated, soft tan lesion with a largest dimension of 1.2 cm. Microscopy reveals areas of hyaline-vascular Castleman’s disease-like pattern. The majority of the lymphoid follicles had atrophic or regressive germinal centers, and some of them are penetrated by capillaries. There was concentric layering of lymphocytes in an onion-skin appearance and one or more penetrating blood vessels. The interfollicular stroma was also prominent with numerous hyperplastic vessels of the post-capillary venule type and plump endothelial lining. (A) concentric layering of lymphocytes in an onion-skin appearance; (B) a “lollipop” appearance; (C) two atrophic germinal centers within a single mantle zone.

Figure 3

An abdominal lymph node biopsy suggests the diagnosis of diffuse large-B cell lymphoma, anaplastic subtype. (A) At low magnification, the normal nodal architecture was totally effaced and the node was diffusely infiltrated by a population of large atypical lymphocytes with a highly characteristic morphology. Extensive infiltration of the perinodal adipose tissue was observed as well. (Haematoxylin and eosin). (B) High magnification show that nuclei were round to oval with fine chromatin; Extensive areas of coagulative necrosis and karyorrhectic nuclei were present. Reed-Sternberg–like forms and giant cells are also prominent and conspicuous nucleoli are seen in these cells. Eosinophilic region was seen near the nucleus, probably representing a prominent Golgi apparatus.