Medical Image of the Week: Tumor-Induced Hypoglycemia

 

Figure 1. CT of the abdomen with IV contrast (axial image) demonstrating numerous large enhancing liver metastases (red oval) and tumor thrombus in the anterior segment branch of the right portal vein (arrow).

A 39 year-old man with a history of widely metastatic (brain, liver and lung) nonseminomatous germ cell tumor was admitted to the hospital with severe abdominal pain and altered mental status. A CT of the abdomen and pelvis with IV contrast revealed a marked increase in the size of the liver metastases, portal vein tumor thrombus and changes of pseudocirrhosis. There were numerous large heterogeneously enhancing masses within the liver parenchyma with central necrosis (Figure 1).

The patient had significant and sustained hypoglycemia, with the lowest glucose recorded of 30 mg/dl. He required multiple IV doses of 50% dextrose and an infusion of 10% dextrose to maintain a serum glucose level greater than 55 mg/dl. His mental status improved with treatment of the hypoglycemia. The patient decided to pursue a palliative approach to care and was discharged with home hospice services.

Tumor-induced hypoglycemia (TIH) is a paraneoplastic syndrome that is uncommon in clinical practice (1). The more common cause of TIH is insulin hypersecretion in the setting of pancreatic beta-cell tumors. Mechanisms that may lead to TIH without insulin hypersecretion include the hypersecretion by tumors of insulin-like growth factor 2 (IGF2) and it’s precursors, insulin-like growth factor 1 (IGF1), somatostatin, and glucagon-like peptide 1. Other pathogenic causes of hypoglycemia include tumor autoimmune hypoglycemia, massive tumor burden, massive tumor liver infiltration, and pituitary or adrenal gland destruction by the tumor. TIH unrelated to pancreatic tumors is called non-islet-cell tumor hypoglycemia (NICTH). The most common cause of NICTH is the hypersecretion of IGF2 and IGF2 precursors by the tumor. This results in increased glucose consumption peripherally and decreased production of glucose in the liver. We did not measure levels of IGF2 in our patient. It was felt the most likely cause of his hypoglycemia was extensive tumor invasion and destruction of the liver due to his advanced disease.

Pavan Parashar MD¹, Meghan Bullock BSN, RN, OCN, Linda Snyder MD²

¹Department of Medicine, Geriatrics, Palliative and General Medicine, Banner University Medical Center-Tucson

²Department of Medicine, Pulmonary, Critical Care and Palliative Medicine, Banner University Medical Center-Tucson

Reference

1. Iglesias P, Díez JJ. Management of endocrine disease: a clinical update on tumor-induced hypoglycemia. Eur J Endocrinol. 2014;170(4):R147-57. [CrossRef] [PubMed] 

Reference as: Parashar P, Bullock M, Snyder L. Medical image of the week: tumor-induced hypoglycemia. Southwest J Pulm Crit Care. 2015;10(5):300-1. doi: http://dx.doi.org/10.13175/swjpcc049-15 PDF

Medical Image of the Week: Leukemic Infiltrates

Figure 1. AP portable chest x-ray demonstrating diffuse bilateral infiltrates.

Figure 2. Histology showing extensive interstitial and perivascular lymphocytic infiltrates.

Figure 3. Immunohistochemical staining for CD8 positive T-cell immunophenotype.

A 50 year-old white man with newly diagnosed, acute T-cell prolymphocytic leukemia presented with progressive exertional dyspnea and non-productive cough. The patient was due to meet with his hematologist that day to discuss initiation of treatment. The patient had not noted fever, chills, night sweats, chest pain, or lower extremity swelling. Blood pressure was 112/60 mm Hg, respiratory rate was 36/minute and labored, pulse was 110/minute and temperature was 37 degrees Celsius. Oxygen saturation measured by pulse oximetry was 62% on room air at rest, and rose to 90% after the application of a 100% non-rebreather mask. Diffuse rales were present on chest auscultation. Marked splenomegaly was present on abdominal examination. Peripheral white blood count was 112.2 K/ul with 99% lymphocytes. Smudge cells were noted. Hemoglobin was 12.9 g/dl and platelet count was 93K/ul. Procalcitonin level was 0.3 pg/ml. The chest radiograph demonstrated diffuse bilateral infiltrates (Figure 1). The patient developed rapidly progressive hypoxemia, was intubated orally, and mechanical ventilation was initiated. Lung biopsies were performed via a video-assisted thoracic surgical approach of the right middle and right lower lobes. Microscopic examination demonstrated extensive leukemic infiltration of the pulmonary interstitium and perivascular space (Figure 2). Immunohistochemical staining showed that the infiltrating cells expressed a CD8 positive T-cell immunophenotype (Figure 3) pattern similar to the patient’s peripheral blood flow cytometry study. Therapy began with an escalating dose of alemtuzumab and intermittent pentostatin, but the patient developed progressive multi-organ failure and expired.

Acute T-cell prolymphocytic leukemia is an aggressive mature T-cell leukemia usually characterized by peripheral blood lymphocytosis and splenomegaly (1). Extramedullary involvement most commonly affects the skin (2). Diffuse interstitial and perivascular pulmonary involvement with respiratory failure has not been previously reported. Pathological involvement of the pulmonary interstitial space should be considered in patients with acute T-cell prolymphocytic leukemia and respiratory insufficiency.

Charles J. VanHook1, Carlyne Cool2, Todd DeBoom3, Robert Fisher4, and

Douglas J. Tangel1

1Department of Intensive Care Medicine

Longmont United Hospital

Longmont, CO

2Department of Pathology and Department of Medicine

University of Colorado and National Jewish Health

Denver, CO

3Department of Pathology

Longmont United Hospital

Longmont, CO

4Department of Oncology

Longmont United Hospital

Longmont, CO

References

1. Dearden CE. T-cell prolymphocytic leukemia. Med Oncol. 2006;23(1):17-22. [CrossRef] [PubMed]
2. Valbuena JR, Herling M, Admirand JH, Padula A, Jones D, Medeiros LJ. T-cell prolymphocytic leukemia involving extramedullary sites. Am J Clin Pathol. 2005;123(3):456-64. [CrossRef] [PubMed]

Reference as: VanHook CJ, Cool C, DeBoom T, Fisher R, Tangel DJ. Medical image of the week: leukemic infiltrates. Southwest J Pulm Crit Care. 2015;10(5):235-7. doi: http://dx.doi.org/10.13175/swjpcc043-15 PDF