JPC SYSTEMIC PATHOLOGY

RESPIRATORY SYSTEM

September 2017

P-N04

 

Signalment (JPC #1758838):  1‑year‑old Icelandic ewe

HISTORY:  This ewe had dyspnea and mucopurulent nasal discharge of 4-5 months duration.

HISTOPATHOLOGIC DESCRIPTION:  Nasal cavity:  Arising from the respiratory epithelium and infiltrating the underlying lamina propria, submucosa and bone is an unencapsulated, poorly circumscribed, densely cellular, multilnodular neoplasm forming papillary projections supported by a fine fibrovascular stalk with tubules, and acini on fine fibrovascular stroma.  Neoplastic cells are ciliated cuboidal to columnar epithelial cells with indistinct cell borders, a moderate amount of finely granular eosinophilic cytoplasm, a single round nucleus with moderately stippled chromatin, and one variably distinct nucleolus.  Anisocytosis and anisokaryosis are mild and the mitotic rate is 1 per 10 HPF.  Occasionally, neoplastic lumina contain a flocculent blue gray material (mucin) admixed with low numbers of neutrophils and necrotic cellular debris.  Multifocally, separating neoplastic cells and expanding the adjacent submucosa there are ectatic lymphatics (edema), abundant mucin, and aggregates of lymphocytes and plasma cells, with fewer macrophages, and neutrophils. Remaining respiratory epithelium is attenuated, mildly eroded or occasionally hyperplastic. Neoplastic cells efface nasal turbinates and there is significant loss of pre-existing nasal bone with replacement by abundant fibrous connective tissue with reactive fibroblasts (fibrosis). Few remaining trabeculae of bone appear fragmented and lytic, or exhibit evidence of bony remodeling with irregular scalloped margins, resting and reversal lines, and new woven bone lined by osteoblasts.

MORPHOLOGIC DIAGNOSIS:  Nasal cavity:  Adenocarcinoma, Icelandic sheep, ovine.

CAUSE:  Enzootic Nasal Tumor Virus (β-retrovirus – ENTV-1 in sheep; ENTV-2 in goats)

CONDITION:  Endemic ethmoidal tumor; enzootic intranasal tumor; enzootic nasal adenocarcinoma; ethmoid tumor; infectious nasal adenopapilloma; ethmoid adenocarcinoma; tumor of the ethmoid olfactory mucosa; papillary adenoma of ethmoid origin

GENERAL DISCUSSION: 

PATHOGENESIS: 

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ULTRASTRUCTURAL FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

COMPARATIVE PATHOLOGY:  

REFERENCES: 

  1. Caswell JL, Williams KJ. Respiratory system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 2. 6th ed. St. Louis, MO: Elsevier; 2016: 560.
  2. Constable PD, Hinchcliff KW, Done SH, Grünberg W. Veterinary Medicine. 11th ed. Louis, MO: Elsevier; 2017:875, 969-970.
  3. Cousens C, Minguijon E, Garcia M, et al. PCR-Based detection and partial characterization of a retrovirus associated with contagious intranasal tumors of sheep and goats. Journal of Virology. 1996;70(11):7580-7583.
  4. Cousens C, Minguijon E, Dalziel RG, et al. Complete sequence of enzootic nasal tumor virus, a retrovirus associated with transmissible intranasal tumors of sheep. Journal of Virology. 1999;73(5):3986-3993.
  5. De Las Heras, Garcia de Jalon JA, Sharp JM. Pathology of enzootic intranasal tumor in thirty-eight goats. Vet Pathol. 1991;28(6):474-481.
  6. Fox KA, Wootton SK, Quackenbush SL, et al. Paranasal sinus masses of Rocky mountain bighorn sheep. Vet Pathol. 2011:48(3)706-712.
  7. Lopez A. Martinson, SA. Respiratory system, mediastinum, and pleurae. In: Zachary JF, eds. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:495-496.
  8. Scocco P, Mariotti F, Ceccarelli P, Fagioli O, Renzoni G, Vitellozzi G. Origin of enzootic intranasal tumor in the goat (Capra hircus): a glycohistochemical approach. Vet Pathol. 2001;38(1):98-104.


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