An Unusual Case of Pancytopenia: The Lessons Learnt

CASE DESCRIPTION

We here report a 36-year-old male who visited emergency department with complaints of weakness of bilateral lower limbs, burning sensation in all four limbs with history of loose stools, and vomiting 5 days back. There was no history of fever, neck stiffness, or rashes. Patient was conscious and on examination had initial pulse rate of 146 per minute and blood pressure of 90 per 66 mm Hg. There was no lymphadenopathy or organomegaly. Neurological examination showed 4+/5 power in both lower limbs and 5/5 in both upper limbs. Neurology consultation was taken, and possibility of Guillain-Barre syndrome (GBS) vs weakness due to hypokalemia (2.6 mEq/L) was initially suggested. Nerve conduction velocity studies were normal. Baseline laboratory investigations showed elevated levels of hepatic enzymes (aspartate aminotransferase—197.7 IU/L, alanine transaminase—281.0 IU/L, and gamma-glutamyl transferase—581.1 IU/L), hypocalcemia (7 mg/dL), and hypoalbuminemia (2.7 g/dL). At presentation, serum sodium, chloride, creatinine, urea, total creatine phosphokinase, magnesium, and phosphorus levels were within normal limits. There was mild prolongation of prothrombin time and activated partial thromboplastin time. The patient was nonreactive for hepatitis A virus, hepatitis E virus, hepatitis B virus, hepatitis C virus, and human immunodeficiency virus. The thyroid function tests were within normal limits. The complete blood counts showed pancytopenia (Hb—11.1 g/dL, total leukocyte count—0.7 × 10⁹/L, absolute neutrophil count—0.3 × 10⁹/L, platelet count—9 × 10⁹/L), for which bone marrow aspiration and biopsy were done. The physician who did bone marrow aspiration described that blood flowed out of the bone marrow aspiration needle hub as soon as needle was inserted into the marrow cavity, an unusual finding during bone marrow procedure. This finding later correlated with increased vascularity and vasodilatation on the bone marrow biopsy. The bone marrow examination showed a significant number of megakaryocytes with large hyperlobated and deeply lobated nuclei (Fig. 1). The erythroid and granulocytic lineages showed maturational shift to left with predominance of early precursors. The cells in erythroid lineage were predominantly early precursors (proerythroblasts, early erythroblasts, and early intermediate erythroblasts), and the occasional late erythroblasts seen show bizarre nuclear shapes and karyorrhexis accompanied by basophilic stippling (Fig. 1C). The cells of granulocytic lineage showed prominent granulation, occasional neutrophil with lobe separation, and myelocytes with persistent cytoplasmic basophilia (Figs 1D and E). There were no atypical cells in the bone marrow aspirate, and eosinophilic lineage was relatively preserved. The bone marrow biopsy showed extensive congested vascular channels with extravasation of red blood cells (RBCs). There was significant megakaryocytic hyperplasia with many megakaryocytes showing large darkly stained hyperlobated nuclei (F). Based on peripheral blood and bone marrow findings, possibility of acute severe insult to marrow was suspected. During the course of next 3 days, patient developed fever, morbilliform rash over flanks and thigh, and delirious behavior. Magnetic resonance imaging of the brain was done which showed diffuse mild gyral thickening. Cerebrospinal fluid examination done was normal. Patient had multiple episodes of polymorphic ventricular tachycardia (pVT) (with very low arterial pressure), which was cardioverted repeatedly by defibrillation of 200 J. Patient went into hypotension requiring inotropic support and drop in left ventricular ejection fraction (LFEF) to 28%. Patient progressed to quadriparesis with 0/5 power in both upper and lower limbs. He also started having raised serum creatinine. Case was discussed in multidisciplinary meeting, and multiple differential diagnoses were considered, including heavy metal poisoning and disseminated viral infections like dengue. On complete evaluation, arsenic blood level came out as 276.48 µg per L and arsenic random urine level was 22324.50 µg per L. Hence, the diagnosis of arsenic poisoning was made with manifestations of cytopenias, corrected QT interval (QTc) prolongation (Fig. 2), and with pVT (Fig. 3), central nervous system, and peripheral nervous system involvement. He was started on injection of British anti-lewisite (BAL) at a dose of 3 mg per kg IM every 6th hour. He had undergone hemodialysis once in view of acute kidney injury and normalized on Day 1 postdialysis. Subsequently, inotropes were stopped, and patient became fully conscious and oriented, shock recovered, liver enzymes normalized, and blood counts recovered. He was tracheostomized in view of quadriplegia with poor respiratory effort and possible prolonged ventilation requirement. Gradually, the patient was given T piece trials with on and off ventilator support and bilevel positive airway pressure support, and was slowly weaned off from noninvasive ventilator support. He started maintaining oxygen saturation at room air. His echo showed LFEF 57% suggesting recovery of arsenic-induced cardiomyopathy. His 24-hour urine arsenic level repeated was 32.31 µg per L; hence, BAL was stopped.

He was afebrile, off inotropes, maintaining hemodynamics, and maintaining oxygen saturation on room air. His power of the upper limb (proximal—2/5 and distal—0/5) and lower limb (proximal—2/5 and distal—0/5) had improved. His attendants took him to some another hospital for further supportive care and rehabilitation. Subsequently, he was lost to follow-up.