Endocrine Abstracts

We present the case of an octogenarian with a major history of lambda light chain myeloma which was treated by a first-line lenalidomide and dexamethasone from June 2018 to September 2019. Patient had also hypertension and valvular heart disease (mechanical valve and anticoagulation by acenocoumarol). In September 2019, a right adrenal mass was incidentally discovered by a renal ultrasonography made for acute kidney injury. The abdominal CT-scan confirmed the presence of a large heterogeneous mass (5 cm) of high density (38 UH) on unenhanced attenuation in the right adrenal gland. 18F-FDG PET-CT showed a moderate FDG-uptake in the adrenal mass and two myelomatous bone lesions (one recent vertebral compaction of L2 and a lesion of the anterior arch of the 5th right rib). Adrenal mass showed high signal in T2 ponderation and in diffusion, without significant fat content on MRI imaging. The lesion characteristics allowed to exclude a benign adenoma and were in favor of a malignant nature. Hormonal evaluation did not demonstrate excessive cortisol (midnight salivary cortisol < 2.5 nmol/l) or other sexual steroids secretion [total testosterone 7.92 nmol/l (N: 6.68–25.70), DHEAs 1.56 µmol/l (N: 0.44–3.34), androstenedione < 0.2 ng/ml (N: 0.1–3.0), oestradiol < 25 ng/l (N: 27.1–52.2)]. Dexamethasone suppression test was not performed because of the treatment with methylprednisolone for the myeloma. 24-hours urine fractionated metanephrines and catecholaminesmeasurements were in the normal ranges. The hypothesis of a non-secreting pheochromocytoma was possible while non-secreting adrenocortical carcinoma (ACC) or metastasis were less probable, especially in the absence of autonomous cortisol secretion for a voluminous ACC and the absence of the localization of a primitive elsewhere for a metastasis. After a multidisciplinary discussion, a biopsy of the mass was performed before removing this neoplastic mass. Anatomapathological examination of the specimen concluded to a lambda light chain monoclonal plasmocytoma, as a rare complication of the myeloma. Solitary plasmacytomas occur most frequently in bone but can also be found outside bone in soft tissues. Extramedullary plasmacytoma (EMP) accounts for only 3% of plasma cell malignancies and adrenal plasmocytomas are extremely rare. Indeed, at our best knowledge, this is the tenth reported case of adrenal plasmacytoma. Among the reported cases, three showed a bilateral gland involving. This case highlights the need of excluding differential diagnoses before surgical treatment of an adrenal neoplasm and the necessity of multidisciplinary input in the management of adrenal tumors.

Acknowledgements

We thank our colleagues of the COMETE network.