Splenic Infarct as the Presenting Manifestation of Essential Thrombocythemia

CASE REPORT

A 34-year-old female presented with severe pricking pain in the left upper abdomen that began 6 days prior, was not relieved with oral analgesics, and was associated with multiple episodes of nonprojectile vomiting. The patient had no history of hypertension or cardiovascular disease and no relevant family history. The primary workup, a blood transfusion, and initial imaging had been done elsewhere before the patient was referred to our institute for further management. Imaging indicated an evolving pseudopancreatic cyst with an ischemic insult of the spleen. On examination in our emergency department, the patient had stable vital signs and tender, moderate splenomegaly. Contrast-enhanced computed tomography repeated at our institution revealed splenic infarction with contained splenic rupture, mild ascites, and left-sided pleural effusion.

Hemoglobin was 7.6 g/dL (reference range, 12-15 g/dL), total leukocyte count was 27 × 10⁹/L (reference range, 4-11 × 10⁹/L), and platelet count was 970 × 10⁹/L (reference range, 150-450 × 10⁹/L). Serum iron studies and serum ferritin revealed evidence of iron deficiency: total iron-binding capacity was 547 μg/dL (reference range, 240-450 μg/dL) and iron was 22 μg/dL (reference range, 60-170 μg/dL).

The patient's case was reviewed in the hematology clinic. The patient was administered iron sucrose 5 mL of 5 mg/mL solution diluted in 100 mL normal saline for 3 consecutive days as per the advice of the hematologist. The patient was initiated on low-dose aspirin because of thrombocytosis. She was managed conservatively for 6 days, during which complete blood counts, iron studies, and inflammatory markers (high sensitivity C-reactive protein and erythrocyte sedimentation rate) were evaluated. She was started on broad-spectrum antibiotics (meropenem injection 1 g intravenously 3 times daily) and continued on the same iron therapy as mentioned above because of leukocytosis and thrombocytosis. Full procoagulant workup (serum homocysteine, fibrinogen, antinuclear antibodies, protein C, protein S, antithrombin III) was negative.

After ruling out all possible causes of secondary thrombosis and given the nonresolution of the patient's symptoms, the decision was made to operate. Our routine protocol is to provide vaccination 14 days before elective splenectomy against Haemophilus influenza, pneumococcus, and meningococcus. Because the patient was taken for surgery on a semi-emergency basis, she could not be vaccinated preoperatively, so vaccination was planned for the postoperative period. She underwent exploratory laparotomy with splenectomy and drainage of the lesser sac collection (approximately 100 mL), which was sterile on culture. Densely thickened and inflamed omentum was wrapped around a devascularized and ruptured spleen.

Histopathologic examination of the splenectomy specimen revealed predominantly infarcted areas with only focally preserved splenic parenchyma, indicating massive splenic infarction (Figure).

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Figure.

(A) Peripheral blood smear (Leishman stain, magnification ×100) shows increased platelets and platelet clumps. (B) Bone marrow aspirate (Giemsa stain, magnification ×40) shows cellular marrow with megakaryocytes cluster (inset: hyperlobated megakaryocyte). (C) Bone marrow biopsy shows increased number of megakaryocytes with hyperlobated nuclei (hematoxylin and eosin stain [H&E], magnification ×40). (D) Photograph of resected spleen with pale cut surface. (E) Photomicrograph of spleen shows infarcted areas (H&E, magnification ×40).

Postoperatively, the patient's platelet count progressively increased (reaching 1,638 × 10⁹/L during the next 8 days), presumably as an acute response to splenectomy. Other reactive causes such as connective tissue disorders, hemolytic anemia, medications, and inflammatory states were ruled out based on history and ancillary laboratory investigations. The ongoing increase in platelet count led us to perform a bone marrow examination on the eighth day of admission that revealed a cellular bone marrow with marked megakaryocytic prominence. Megakaryocytes displayed large to giant forms with abundant mature cytoplasm and conspicuously hypersegmented staghorn–like nuclei. These findings were consistent with essential thrombocythemia.

After a hospital stay of 10 days, the patient was discharged on oral cefuroxime 500 mg twice daily, aceclofenac 100 mg twice daily, and pantoprazole 40 mg once daily for 5 days. She returned for follow-up after 7 days for suture removal and laboratory investigations.

Molecular studies were performed to complete the workup for essential thrombocythemia. The test was negative for the BCR-ABL1 mutation, but the JAK2 V617F mutation was detected, meeting the criteria of essential thrombocythemia.

The patient was vaccinated 1 month postoperatively and maintained on oral aspirin 75 mg once daily. She was followed up every 3 months during the first year and every 6 months during subsequent years. Her platelet count stabilized to 380 × 10⁹/L after 1 month, so she did not require chemotherapy. She continues to do well after 18 months of follow-up with no evidence of infection.