Excessive muscle paralysis due to pulmonary carcinoid -a case report

Abstract

We present the case of a 58-year-old woman with a renin secreting typical bronchopulmonary carcinoid. This patient showed hypotension, constipation and fatigue due to extensive hypokaliemia (K =1.9 meq/L). Aldosterone (102.7 ng/100 mL) and renin (46 ng/mL) were excessively elevated at that time, but cortisol level was normal. Routine chest roentgenography and computed tomography revealed a nodular lesion in the upper left lung lobe, which was suspicious for a neurosecretory pulmonary tumor. The final diagnosis was made by using bronchoscopic procedures and the histologically diagnosis was compatible as a typical pulmonary carcinoid. The tumor was resected curatively, and the renin and aldosterone level became normal. A year after the patient looks healthy.

Keywords: hypokaliemia; neurosecretory pulmonary tumor; pulmonary carcinoid; renin.

Figure 1

Chest X-ray revealed a nodule without cavitations to the upper lung lobe of the left lung.

Figure 2

Thorax CT scanning revealed a left lung nodule (diameter 21 ×14 mm), at the upper anterior lung lobe without collateral lymphadenopathy.

Figure 3

Photomicrograph shows small nests of uniform high-grade epithelial endocrine cells, without necrosis or mitosis (<2 mm²), classified as a typical carcinoid tumor of the lung (original magnification, ×100 and ×300; hematoxylin-eosin stain).

Figure 4

The renin-angiotensin-aldosterone axis and molecular pathways of sodium reabsorption in the nephron. Notes: A cartoon of a nephron is shown, with sodium-reabsorbing cells of the thick ascending limb of the loop of Henle (TALLH), distal convoluted tubule (DCT), and collecting duct (CD). The latter is responsible for fine regulation via the aldosterone-activated mineralocorticoid receptor (MR). In all cells, sodium exits the basolateral compartment via the Na/K-ATPase (not shown). Renin levels stimulate the the axis initiating the transformation of angiotensinogen to angiotensin I. Aldosterone synthesis is controlled by angiotensin II. The figure taken and adjusted from reference . Abbreviations: Na, sodium; K, potassium; Cl, chloride.