JPC SYSTEMIC PATHOLOGY

INTEGUMENT SYSTEM

October 2016

I-N15

 

SLIDE A Signalment (JPC #2648402): Age and breed not specified, dog

HISTORY: Dermal mass

HISTOPATHOLOGIC DESCRIPTION:  Haired skin and subcutis:  Expanding the subcutis and elevating the overlying epidermis and dermis is a 9 x 6 mm, well-circumscribed, unencapsulated, sparsely cellular neoplasm composed of spindle cells arranged in long, thick, interlacing streams and bundles and supported by an abundant collagenous matrix.  Neoplastic cells have indistinct cell borders and cytoplasm, an oval to elongate nucleus with finely stippled chromatin and a variably distinct nucleolus.  The mitotic rate is less than 1 per 10 hpf.  Multifocally within the neoplasm and adjacent dermis are few lymphocytes, plasma cells, and mast cells.  Multifocally, within the superficial dermis, collagen fibers are mildly separated by amphophilic, beaded to fibrillar mucin and mildly ectactic apocrine glands are lined by attenuated epithelium.

MORPHOLOGIC DIAGNOSIS: Haired skin: Fibroma, breed unspecified, canine.

SLIDE B
Signalment (JPC #2648388): Age and breed not specified, cat

HISTORY: None

HISTOPATHOLOGIC DESCRIPTION:  Mucosa:  Infiltrating and effacing the subepithelial connective tissue, elevating the overlying epithelium, and extending to deep and lateral margins is a moderately cellular neoplasm composed of spindle cells arranged in irregular, broad, interlacing streams and bundles to form a “herringbone” pattern supported on an abundant collagenous matrix. Neoplastic cells have indistinct cell borders and cytoplasm, an oval to elongate nucleus with finely stippled chromatin, and an indistinct nucleolus. There is moderate anisokaryosis.  Mitoses are less than 1 per 10 hpf.  Blood vessels within the neoplasm are lined by plump, reactive endothelium. Multifocally, within and surrounding the neoplasm, are few lymphocytes, plasma cells, mast cells, and hemorrhage.

MORPHOLOGIC DIAGNOSIS: Mucosa: Fibrosarcoma, breed unspecified, feline.

SLIDE C
strong>Signalment (JPC #4038131): Chesapeake Bay retriever, age unknown

HISTORY: None

HISTOPATHOLOGIC DESCRIPTION: Haired skin and subcutis: Expanding the dermis and subcuticular tissue and elevating the overlying epidermis is an unencapsulated, well demarcated, moderately cellular, neoplasm consisting of spindle cells arranged in thin streams surrounding and separating thick bundles of brightly eosinophilic homogenous birefringent material (hyalinized collagen) within a fine fibrovascular stroma. Neoplastic cells have indistinct cell borders, a scant amount of finely fibrillar eosinophilic cytoplasm and an elongate central nucleus with finely stippled chromatin and indistinct nucleoli. Anisocytosis and anisokaryosis are mild. The mitotic rate is less than 1 per 10 HPF. Admixed with neoplastic cells are a small number of lymphocytes and plasma cells.

MORPHOLOGIC DIAGNOSIS: Haired skin and subcutis: Fibroma, keloidal, dermal, Chesapeake Bay retriever, canine

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS (histologic lesions):

COMPARATIVE PATHOLOGY:

REFERENCES:

  1. Bell CM, Schwarz T, Dubielzig RR. Diagnostic features of feline restrictive orbital myofibroblastic sarcoma. Vet Pathol. 2011;48(3):742-750.
  2. Ciekot PA, Powers BE, et al. Histologically low-grade, yet biologically high-grade, fibrosarcomas of the mandible and maxilla in dogs: 25 cases (1982-1991).       J Am Vet Med Assoc. 1994 Feb 15;204(4):610-5.
  3. Coffee LL, Case JW, Bowser PR. Pathology of tumors in fish associated with retroviruses: A review. Vet Pathol.       2013;50(3):390-403.
  4. Dennis MM, McSporran KD, Bacon NJ, Schulman FY, Foster RA, Powers BE. Prognostic factors for cutaneous and subcutaneous soft tissue sarcomas in dogs. Vet Pathol. 2011;48:73-84.
  5. Goldschmidt MH, Hendrick MJ. Tumors of the skin and soft tissues. In: Tumors in Domestic Animals. 4th ed. Ames, IA: Iowa State Press; 2002:84-94.
  6. Gross TL, Ihrke PJ, Walder EJ, et al. Fibrous tumors. In: Gross TL, Ihrke PJ, Walder EJ, et al. eds. Skin Diseases of the Dog and Cat. 2nd ed. Ames, IA: Blackwell Science Ltd; 2005:716-734.
  7. Hargis AM, Ginn, PE. The integument. In: Zachary JF, McGavin MD, eds. Pathologic Basis of Veterinary Disease. 5th ed. St. Louis, MO: Elsevier Mosby; 2012:1082.
  8. Hendrick MJ, Mahaffey EA, Moore FM, et al. Histologic Classification of Mesenchymal Tumors of Skin and Soft Tissues of Domestic Animals. 2nd series, Vol 2. Washington, DC: Armed Forces Institute of Pathology; 1998.
  9. Klopfleisch R, Meyer A, Lenze D, et al. Canine cutaneous peripheral nerve sheath tumors versus gibrosarcomas can be differentiated by neuroectodermal marker genes in their transcriptome. J Comp Path. 2013;148(2-3):197-205.
  10. Knight C, Fan E, Riis, R, et al. Inflammatory myofibroblastic tumors in two dogs. Vet Pathol. 2009;46(2):273-276.
  11. Little LK, Goldschmidt M. Cytologic appearance of a keloidal fibrosarcoma in a dog. Vet Clin Pathol. 2007;36:364-367.
  12. Mauldin EA, Peters-Kennedy J. Integumentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:725-6.
  13. Meyer, A, Klopfleisch R. Multiple polymerase chain reaction markers for the differentiation of canine peripheral nerve sheath tumours versus canine fibrosarcomas. J Comp Path. 2014;150(2-3):198-203.
  14. Mikaelian I and Gross TL. Keloidal fibromas and fibrosarcomas in the dog. Vet Pathol.       2002;39:149-153.
  15. Scott DW, Miller WH, Griffin CE. Neoplastic and non-neoplastic tumors. In: Scott DW, Miller WH, Griffin CE, eds. Small Animal Dermatology. 6th ed. Philadelphia, PA: WB Saunders Company; 2001:1281-1291.
  16. Uzal FA, Plattner BL, Hostetter JM. Alimentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 2. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:27.
  17. Valentine BA, Martin JM. Prevalence of neoplasia in llamas and alpacas (Oregon State University, 2001-2006). J Vet Diagn Invest. 2007;19(2):202-204.
  18. Von Bomhard W, Goldschmidt MH, Shofer FS, et al. Cutaneous neoplasms in pet rabbits: A retrospective study. Vet Pathol. 2007;44(5):579-588.
  19. Zanatta M, Bettini G, Scarpa F, et al. Nodular dermatofibrosis in a dog without a renal tumour or a mutation in the folliculin gene. J Comp Path. 2013;148(2-3):248-251.


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