JPC SYSTEMIC PATHOLOGY
HEMOLYMPHATIC SYSTEM
March 2018
H-B01

 

SLIDE A

SIGNALMENT (JPC #1758391): A 4-year-old bull.

HISTORY: Over a 3-day period, 3 bulls were found dead without previous signs in a pasture with 2 other bulls and 25 cows 

HISTOPATHOLOGIC DESCRIPTION: Spleen: Diffusely, there is severe lymphoid depletion with necrosis and collapse of the white pulp characterized by lymphocytolysis. The trabecular meshwork of the red pulp is widely separated by abundant blood (congestion), and scattered throughout are a multitude of large (1x6 um) bacilli with squared ends which occur individually or in short chains. Multifocally, endothelial cells are hypertrophied and there are intravascular bacilli; vessel walls are mildly thickened by edema and fibrin. There is diffuse intracapsular hemorrhage and expansion of the pericapsular fibroadipose tissue by hemorrhage and fibrin, admixed with numerous bacilli.

Lung: Diffusely, alveolar septa are fragmented and necrotic and expanded up to ten times normal by abundant hemorrhage and fibrin and numerous large (1x6 um) bacilli that occur individually or in short chains of 3-4 organisms. Bacilli infiltrate bronchial and bronchiolar subepithelial connective tissue which is similarly expanded by hemorrhage, edema, and few neutrophils, and extend into the lumen. Bronchial-associated lymphoid tissue (BALT) is multifocally depleted with occasional lymphocytolysis and replacement by hemorrhage and additional bacilli.

MORPHOLOGIC DIAGNOSIS: 1. Spleen: Lymphoid depletion and necrosis, diffuse, marked, with diffuse congestion, capsular and pericapsular hemorrhage, and myriad intra- and extravascular bacilli, bovine. 

  1. Lung: Pneumonia, interstitial, necrohemorrhagic, acute, diffuse, moderate with BALT necrosis and myriad bacilli.

SLIDE B

SIGNALMENT (JPC #531135): Age unknown, breed not specified pig.

HISTORY: Sections from a large, brick-red cervical lymph node found in a pig at slaughter

HISTOPATHOLOGIC DESCRIPTION: Lymph node: There are multifocal to coalescing extensive areas of coagulative necrosis of lymphoid tissue characterized by loss of cellular detail, retention of cell architecture, and abundant karryorhectic and cellular debris admixed with fibrin, edema and hemorrhage. Within remaining lymphoid follicles, there is marked lymphoid depletion with central lymphocytolysis. Sinuses contain moderate numbers of degenerate neutrophils, lymphocytes, and macrophages admixed with fibrin, edema, hemorrhage, cellular and karyorrhectic debris (necrosis), and variably-sized colonies of 1um cocci. Multifocally, small blood vessels contain fibrin thrombi.  The pericapsular fibroadipose tissue is moderately infiltrated by many degenerate and viable neutrophils, fewer lymphocytes, plasma cells, macrophages, and fibrin and edema.

SLIDE C

Lymph node (B&B): Numerous individual and short chains of dark blue staining (gram-positive) bacilli and variably-sized colonies of small cocci are scattered throughout the necrotic debris.

MORPHOLOGIC DIAGNOSIS: Lymph node: Lymphadenitis, necrotizing, diffuse, severe, with fibrinosuppurative perilymphadenitis and numerous short chains of gram-positive bacilli and cocci, porcine.

ETIOLOGIC DIAGNOSIS: Pulmonary, splenic, and lymphoid anthrax

CAUSE: Bacillus anthracis

CONDITION: Anthrax

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

COMPARATIVE PATHOLOGY:

REFERENCES:

  1. Constable PD, Hinchcliff KW, Done SH, Grunberg W. Veterinary Medicine: A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs, and Goats. 11th ed. St. Louis, MO: Elsevier; 2017:2011-2014.
  2. Gates C, Elkin B, Dragon D. Anthrax. In: Williams E, Barker I, eds. Infectious Diseases of Wild Mammals. 3rd ed. Ames, IA: Iowa State University Press; 2001:396-412.
  3. Goel AK. Anthrax: A disease of biowarfare and public health importance. World J Clin Cases. 2015;13(1):20–33.
  4. Miller RE, Fowler ME. Zoo and Wild Animal Medicine. Vol. 8. St. Louis, MO: Elsevier Saunders; 2015: 484-485, 527, 562, 617-620.
  5. Shadomy SV, Smith TL. Zoonosis update: Anthrax. J Am Vet Med Assoc. 2008;233:63-72.
  6. Stewart GC, Thompson BM. Bacillus. In: McVey DS, Kennedy M, Chengappa MM, eds. Veterinary Microbiology. 3rd ed. Ames, IA: Wiley-Blackwell;2013:206-210.
  7. Twenhafel NA. Pathology of inhalational anthrax animal models. Vet Pathol. 2010;47(5):819-30.
  8. Valli VEO, Kiupel M, Bienzle D. Hematopoietic system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 3. 6th ed. St. Louis, MO: Elsevier; 2016:171-174.
  9. Watson JL. Diseases of the hematopoietic and hemolymphatic systems. In: Smith BP, ed. Large Animal Internal Medicine. 5th ed. St. Louis, MO: Elsevier Mosby; 2015:1077-1078.
  10. Zachary JF. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:161,168,176,380-381,782,1078-1079.

 

 


Click the slide to view.



Click on image for diagnostic series.



Back | Home | Contact Us | Links | Help |