Secondary distal renal tubular acidosis and sclerotic metabolic bone disease in seronegative spondyloarthropathy.

Adults with distal renal tubular acidosis (dRTA) commonly present with hypokalaemia (with/without paralysis), nephrolithiasis/nephrocalcinosis and vague musculoskeletal symptoms. All adults with dRTA should be thoroughly evaluated for systemic diseases, certain medications and toxins. The leading cause of acquired or secondary dRTA in adults is primary Sjögren syndrome (SS); however, other collagen vascular diseases (CVDs) including seronegative spondyloarthropathy (SSpA) may at times give rise to secondary dRTA. Metabolic bone disease is often encountered in adults with dRTA, and the list includes osteomalacia and secondary osteoporosis; sclerotic metabolic bone disease is an extremely rare manifestation of dRTA. Coexistence of dRTA and sclerotic bone disease is seen in primary dRTA due to mutation in CA2 gene and acquired dRTA secondary to systemic fluorosis. Primary SS and SSpA, rarely if ever, may also lead to both secondary dRTA and osteosclerosis. Circulating autoantibodies against carbonic anhydrase II and possibly calcium sensing receptor may explain both these features in patients with CVD.

Continuous and progressive 'wash-in' without 'wash-out' of contrast in adrenal mass: a useful feature of ganglioneuroma.

Computed tomography (CT) scan is a useful and widely performed diagnostic modality to evaluate adrenal masses. Nature of the mass determines the degree of attenuation both in unenhanced and in different phases of contrast enhancement. Benign neurogenic tumours like ganglioneuroma mimicks pheochromocytoma and adrenocortical carcinoma in non-contrast CT scan. The 'adrenal protocol' routinely calculates the wash-out pattern at delayed venous phase (DVP) (15 min) following contrast administration to differentiate majority of benign masses from the malignant ones. Ganglioneuromas typically exhibit continuous wash-in of contrast where enhancement gradually increases to attain its peak in DVP. Such wash-in pattern is different from the wash-out pattern observed in pheochromocytomas or adrenocortical adenomas or carcinomas. Presence of this wash-in pattern provides a useful clue to the clinician for underlying ganglioneuroma in hormonally inactive adrenal masses with suspicious morphological appearances. This wash-in pattern also effectively rules out any malignant potential of ganglioneuroma, and thus helps in preoperative decision-making.