Indian Journal of Pathology and Microbiology
Home About us Instructions Submission Subscribe Advertise Contact e-Alerts Ahead Of Print Login 
Users Online: 3683
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size

  Table of Contents    
Year : 2012  |  Volume : 55  |  Issue : 4  |  Page : 572-573
A fatal case of bone marrow embolism of unknown cause masquerading clinically as dengue shock syndrome

1 Department of Pathology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India
2 Department of Internal Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India

Click here for correspondence address and email

Date of Web Publication4-Mar-2013


Bone marrow fat embolism usually occurs following multiple bone fractures, intraosseous surgical procedures, following vigorous cardiac resuscitation, ecclampsia, sickle cell anemia, malignancies, etc. We present a case of 70-year-old male who presented with fever, cough with expectoration, respiratory distress, altered sensorium, hypotension and thrombocytopenia, and diagnosed to have dengue shock syndrome and expired within 1 day of admission. Postmortem lung biopsy revealed bone marrow fat embolism.

Keywords: Bone marrow embolism, incidental, postmortem, shock

How to cite this article:
Selvi SK, Kar R, Vadivelan M, Subrahmanyam DK. A fatal case of bone marrow embolism of unknown cause masquerading clinically as dengue shock syndrome. Indian J Pathol Microbiol 2012;55:572-3

How to cite this URL:
Selvi SK, Kar R, Vadivelan M, Subrahmanyam DK. A fatal case of bone marrow embolism of unknown cause masquerading clinically as dengue shock syndrome. Indian J Pathol Microbiol [serial online] 2012 [cited 2023 Mar 29];55:572-3. Available from:

   Introduction Top

The fat embolism syndrome was first described clinically by Von Bergmann, [1] who cared for a man with a broken femur and symptoms of the syndrome in 1873. Fat embolism is caused by bone marrow components, in the form of cell debris and yellow bone marrow, entering into the systemic circulation and into the parenchyma of the lungs via the venous sinus. [2] Fat embolism syndrome (FES), however, is the symptomatic manifestation of fat embolism with symptoms such as respiratory failure, thrombocytopenia, or cerebral confusion, which occur within 48 h after trauma in most patients. [3]

   Case Report Top

A 70-year-old male presented with fever for 5 days, cough with expectoration, and respiratory distress for 3 days, giddiness and altered sensorium for 2 days. On examination, he was found to have hypotension which did not improve even after administration of ionotropics. Complete hemogram of blood showed normocytic normochromic anemia with thrombocytopenia. The patient was clinically diagnosed to have dengue shock syndrome and was managed symptomatically.

Serial investigations revealed middle and upper lobe infiltrates on chest X-ray and the patient expired within 1 day of admission due to persistent hypotension, shock, severe respiratory distress, and massive hemoptysis. Subsequently, the dengue serology was also reported negative.

We received the postmortem lung and liver biopsy. The liver biopsy showed non-specific findings secondary to shock. The lung biopsy showed a pulmonary vein with bone marrow fat embolism comprising marrow fat spaces, megakaryocyte, myeloid, and erythroid precursors [Figure 1]a and b. The surrounding lung parenchyma showed diffuse intra-alveolar hemorrhage [Figure 1]a and features of diffuse alveolar damage like focal hyaline membrane change [Figure 1]c.
Figure 1: (a) Pulmonary vein showing bone marrow embolism with the surrounding lung parenchyma showing intra-alveolar hemorrhage (H and E, ×100); (b) High power of the embolus comprising megakaryocyte, myeloid, and erythroid precursors (H and E, ×100); (c) Diffuse alveolar damage (Hyaline membrane change) of adjacent lung parenchyma (H and E, ×100)

Click here to view

   Discussion Top

Fat embolism develops due to lipid globules being released from bone marrow and soft tissue which can be associated with or without bone marrow elements. The causes for fat embolism can be traumatic or non-traumatic. The traumatic causes are common where there is a mechanical disruption of marrow elements/adipocytes which includes bone fractures, intraosseous procedures/surgery, bone marrow transplant, soft tissue injuries, vigorous cardiac resuscitation, ecclampsia, and liposuction. The causes of nontraumatic fat embolism includes severe burns, acute pancreatitis, hepatic steatosis, sickle cell anaemia, diabetes mellitus, prolonged steroid therapy, malignancy, and total parenteral nutrition. [4],[5]

The pathophysiology of fat embolism syndrome has not yet been definitively characterized. A mechanical theory holds that the embolization event results from a transient rise in the pressure in a fat-containing cavity in association with torn blood vessels, allowing escape of marrow or adipose fat cells into the circulation. [6] Two alternative biochemical theories posit explanations for fat embolism syndrome, both of which could account for the observation of the syndrome in nontraumatic settings. In one, fat droplets already in the circulation are broken down at distal sites to free fatty acids, which then exert a local toxic effect on the tissues. This theory explains the appearance of petechiae and the histologic changes in pneumocytes in association with fat-embolism-induced acute respiratory distress syndrome (ARDS). [7] The obstructive explanation for fat embolism syndrome proposes that free fatty acids are mobilized by circulating catecholamines. Fat droplets in the circulation eventually coalesce and embolize, causing destructive effects. [8] Fat embolism syndrome can occur in immediate conjunction with a precipitating factor or it can be delayed for up to 3 days, although 85% of cases are apparent within 48 h.

Gurd and Wilson [9] proposed the most widely accepted guidelines for the diagnosis of fat embolism syndrome and have been modified several times since, which require at least one sign from the major and at least four signs from the minor criteria. [10] Looking back at the clinical details in retrospect after the histopathology, this case satisfied the criteria for fat embolism syndrome as enumerated below:

2 major criteria

  1. Cerebral involvement [Giddiness, altered sensorium].
  2. Respiratory insufficiency.
9 minor criteria

  1. Pyrexia.
  2. Tachycardia [110/min]
  3. Confusion.
  4. Sustained respiratory rate >35/minute, in spite of sedation.
  5. Unexplained drop in platelet count (16,000/cumm).
  6. Anemia.
  7. Elevated ESR [55 mm/hr]
  8. Renal signs [oliguria, bilateral pedal edema].
  9. Diffuse alveolar infiltrates snow storm appearance on chest X-ray.
The diagnostic workup of a patient suspected of having fat embolism syndrome should include serial arterial blood gas measurements, as hypoxemia is one of the cardinal features. Serial chest radiographs can be used to observe the progression of ARDS infiltrates in the lungs, although it should be noted that chest radiographic changes are often not apparent in the initial stages of the syndrome. An ECG might show a new right bundle-branch block or nonspecific T-wave changes. A late laboratory marker of fat embolism syndrome is serum lipase, which becomes elevated 3 to 5 days after embolization and peaks at 5 to 8 days. Fat embolism can be detected by means of trans-esophageal echocardiography in more than 90% of patients suffering from fractures of the long bones. [2]

In our case, the cause for fat embolism remained unknown. The patient did not have any history of trauma or exposure to other predisposing causes known to cause fat embolism syndrome.

   Conclusion Top

This is a rare case of bone marrow embolism incidentally detected in postmortem lung biopsy in a case of clinically suspected dengue shock syndrome. This finding could explain the cause of death in this patient to be due to bone marrow fat embolism syndrome of unknown cause.

   References Top

1.Von Bergmann E. Ein fall todlicher fettembolie. Berl Klin Wochenscher 1873;10:385.  Back to cited text no. 1
2.Bulger EM, Smith DG, Maier RV, Jurkovich GJ. Fat embolism syndrome. A 10-year review. Arch Surg 1997;132:435-9.  Back to cited text no. 2
3.Levy D. The fat embolism syndrome. A review. Clin Orthop Relat Res 1990;261:281-6.  Back to cited text no. 3
4.Meller A, Soni N. Fat embolism. Anaesthesia 2001;56:145-54.  Back to cited text no. 4
5.Karayel F, Arican N, Kavas G, Turan AA, Pakis I. Maternal death due to non-traumatic fat embolism. J Forensic Sci 2005;50:1201-3.  Back to cited text no. 5
6.Mortan KS, Kendall MJ. Fat embolism. Its production and source of fat. Can J Surg 1965;8:214-20.  Back to cited text no. 6
7.Fonte DA, Hausberger FX. Pulmonary free fatty acids in experimental fat embolism. J Trauma 1971;11:668-72.  Back to cited text no. 7
8.Baker PL, Pazell JA, Peltier LF. Free fatty acids, catecholamines, and arterial hypoxia in patients with fat embolism. J Trauma 1971;11:1026-30.  Back to cited text no. 8
9.Gurd AR, Wilson RI. The fat embolism syndrome. J Bone Joint Surg Br 1974;56B:408-16.  Back to cited text no. 9
10.Shaikh N. Emergency management of fat embolism syndrome. J Emerg Trauma Shock 2009;2:29-33.  Back to cited text no. 10
[PUBMED]  Medknow Journal  

Correspondence Address:
Rakhee Kar
Department of Pathology, JIPMER, Puducherry
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0377-4929.107827

Rights and Permissions


  [Figure 1]

This article has been cited by
1 Sudden death following accidental ingestion of a button battery by a 17-month-old child: a case study
T. Guinet,J. M. Gaulier,C. Moesch,J. Bagur,D. Malicier,G. Maujean
International Journal of Legal Medicine. 2016; 130(5): 1291
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  

   Case Report
    Article Figures

 Article Access Statistics
    PDF Downloaded96    
    Comments [Add]    
    Cited by others 1    

Recommend this journal