Hemolytic anemia in a female patient presenting for routine cholecystectomy.

Dear Editor,

Gall stones are of common occurrence and frequently cause acute abdominal pain and are managed by cholecystectomy. Cholecystectomy, whether open or closed, is among the most commonly performed surgeries worldwide. The cause of cholelithiasis is infrequently investigated properly. We report a case of a middle-aged female patient who presented for routine laparoscopic cholecystectomy and pre-operative chest X-ray which lead to the diagnosis of hemolytic anemia as the cause of gall stones with compensatory extramedullary hematopoiesis (EMH).

A middle-aged female patient presented to the surgery out-patient department for routine laparoscopic cholecystectomy. She recently had an episode of acute epigastric pain and was diagnosed as cholecystitis with cholelithiasis on ultrasound abdomen. During the pre-anesthetic work-up for cholecystectomy, she was referred to the radiology department for routine chest X-ray. Her routine investigations were all normal except for mild anemia (Hb –9.8 gm/dl). X-ray of the chest Postero-anterior and Lateral view showed well-defined mediastinal masses manifesting as increased retro-cardiac paravertebral soft-tissue density [Figure 1a] and as spine sign on Lateral view [Figure 1b]. Detailed history for any chest complaints was negative except for mild dyspnea and occasional cough. There was no family history of any hematological disorder. The patient was advised computed tomography (CT) of the thorax for evaluation of retro-cardiac opacity. Contrast-enhanced CT showed multiple, well-defined, lobulated, bilateral paravertebral masses with no evidence of calcification or fat density within masses and mild homogenous enhancement [Figure 2a and b]. There was no evidence of underlying bone expansion or destruction or extension into neural foramina. The lesions displaced adjacent lung field suggesting extra-parenchymal location of the lesions. Additional significant findings seen on CT in this patient were presence of gall stones, hepatomegaly, and spleenomegaly [Figure 2c and d]. Based on these radiological findings of bilateral posterior mediastinal masses; Lymphoma, Multiple Myeloma, Metastasis, EMH and Pott's spine were important differentials considered in this patient. Further hematological work-up of the patient revealed – Hemoglobin 9.8 gm/dl, hematocrit 35.6%, mean red cell volume 102 fl with increased reticulocyte count, i.e., 8%. The blood film contained about 28% spherocytes with markedly increased erythrocyte osmotic fragility on osmotic fragility lysis test, thereby suggesting the diagnosis of hereditary spherocytosis (HS). There was no evidence of any clinically palpable lymphadenopathy or retroperitoneal lymph nodes on ultrasound or CT. CT-guided fine-needle aspiration cytology of the paravertebral mass was performed which showed aggregates of erythroid and myeloid precursors with usual morphology along with megakaryocytes suggesting extramedullary hematopoiesis. Therefore, the diagnosis of HS with compensatory EMH was confirmed.

Figure 1

X-ray Chest Postero-anterior and Lateral view shows well defined mediastinal masses manifesting as increased retro cardiac paravertebral soft tissue density (a) and as spine sign on Lateral view (b)

Figure 2

Contrast enhanced computed tomography mediastinal window shows bilateral posterior mediastinal masses displacing adjacent lung field with no evidence of calcification or fat density within the masses (a and b). Gall stones, hepatomegaly and spleenomegaly is also noted (c and d)

HS is the most common red cell membrane disorder with an autosomal dominant or, less commonly, an autosomal recessive pattern of inheritance. The peripheral blood smears show spherocytes with an increase in osmotic fragility. The pattern of expression of this disease is highly variable. It varies from clinically asymptomatic condition to a severe, life-threatening presentation.[12]

The cause of EMH in HS, or for that matter in all hemolytic anemia, is a compensatory mechanism in response to destruction of red blood cells leading to the production of myeloid and erythroid elements at ectopic sites. Other conditions that predispose to EMH include myelofibrosis, polycythemia rubra vera, and replacement of bone marrow by carcinoma or lymphoma. EMH commonly occurs in spleen, liver, lymph nodes, and mediastinum and less commonly in skull, kidney, or retroperitoneum.[1-4] Intrathoracic EMH is a relatively rare entity, commonly seen in the posterior mediastinum, and are frequently asymptomatic. They are frequently identified incidentally, as in our case. Rarely, they can produce symptoms of spinal cord compression if they extend to an epidural location.[56] The investigation of choice for EMH is magnetic resonance imaging which shows an isointense mass with a high signal intensity rim on T1-weighted images and a homogenous hyper intensity on T2-weighted images.[36]

Treatment of patients with EMH is considered only if complications occur. Treatment options are surgery, radiation therapy, blood transfusions, or their various combinations.[6] Relatively small doses of radiotherapy are quite effective as EMH masses are highly radiosensitive.[67] Surgical removal of spleen is considered the treatment of choice for patients with EMH due to HS because it eliminates the main site of red cell destruction.[8]

This case highlights the importance of pre-operative chest X-ray in a patient having symptomatic gallstones and an un-investigated mild anemia which lead us to the diagnosis of HS with EMH. The routine pre-operative chest X-rays, however, still remains a debated issue and probably unjustified if we do it in all the cases.[9]