HISTOPATHOLOGY. Shannon Martinson

Transcription

1 HISTOPATHOLOGY Shannon Martinson March 2013

2 Case #1 History: 8 year old beagle Neck pain for the past couple of weeks Paresis, followed by paralysis developed over the past few days

3 Gross Description courtesy of Dr L Pack, AVC

4 Gross Description A nodular mass is present within the second cervical vertebrae. It protrudes into the spinal canal (compressing the spinal cord at this site) courtesy of Dr L Pack, AVC

5 Gross Description

6 Gross Description On section, the soft pink gelatinous mass is present within the marrow cavity of the vertebral body with slight dorsal protrusion into the spinal canal.

7 Differential Diagnoses:

8 Differential Diagnoses: Multiple myeloma, osteosarcoma, osteomyelitis

9 Histology

10 Histology

11 Histologic Description:

12 Histologic Description: There is a marked increase in the cellularity of the bone marrow (100% cells / 0% adipose tissue)

13 Histologic Description:

14 Histologic Description: Sheets of tightly packed neoplastic round cells infiltrate the marrow cavity of the vertebral body

15 Histologic Description:

16 Histologic Description: The cells are round with distinct cell margins and a moderate amount of pale basophilic cytoplasm occasionally with perinuclear clearing. The nuclei are eccentric and round with coarse clumped hyperchromatic chromatin

17 Case #1 Histologic Description (summary): Sheets of tightly packed neoplastic round cells infiltrate the marrow cavity of the vertebral body. The cells are round with distinct cell margins and a moderate amount of pale basophilic cytoplasm with occasional perinuclear clearing. The nuclei are round with clumped chromatin Morphologic Diagnosis:

18 Case #1 Histologic Description (summary): Sheets of tightly packed neoplastic round cells infiltrate the marrow cavity of the vertebral body. The cells are round with distinct cell margins and a moderate amount of pale basophilic cytoplasm with occasional perinuclear clearing. The nuclei are round with clumped chromatin Morphologic Diagnosis: Multiple Myeloma, vertebrae Possible clinical pathology findings:

19 Case #1 Histologic Description (summary): Sheets of tightly packed neoplastic round cells infiltrate the marrow cavity of the vertebral body. The cells are round with distinct cell margins and a moderate amount of pale basophilic cytoplasm with occasional perinuclear clearing. The nuclei are round with clumped chromatin Morphologic Diagnosis: Multiple Myeloma, vertebrae Possible clinical pathology findings: Hypergammaglobulinemia, hypercalcemia, Bence-Jones proteinuria

20 courtesy of Dr A Matthews AVC Ancillary / helpful diagnostic findings courtesy of Dr. A Matthews, AVC Hypercalcemia increased osteoclastic activity within bone lesions Hypergammaglobulinemia clonal neoplastic plasma cells secrete immunoglobulins (fragments) of one class Bence-Jones proteinuria Immunoglobulin light chains pass through glomerulus into urine Radiographs showed punched out lesions in the vertebrae

21 Case #2 Signalment: 1.5 year old, laying hen History: The bird has been down for a day and has not been eating All images for this case were provided by Dr Heather Fenton, AVC

22 Spleen Liver Bone

23 Spleen Gross Description

24 Spleen Gross Description The spleen is markedly enlarged and misshapen with coalescent yellow-tan nodules scattered throughout

25 Spleen Gross Description

26 Spleen Gross Description These extend into the parenchyma on cut surface replacing most of the normal architecture

27 Spleen Histologic Description

28 Spleen Histologic Description Discrete eosinophilic nodules are present within the spleen.

29 Spleen Histologic Description

30 Spleen Histologic Description The nodules are composed of central regions of necrosis surrounded by a thick cellular rim. What are the cells?

31 Spleen Histologic Description The nodules are composed of central regions of necrosis surrounded by a thick cellular rim. What are the cells?

32 Spleen Histologic Description The nodules are composed of central regions of necrosis surrounded by a thick cellular rim. What are the cells?

33 Spleen Histologic Description The cells consist primarily of epithelioid macrophages and rare heterophils. Admixed with these cells are occasional lymphocytes, plasma cells and fibroblasts and what other cell type?

34 Spleen Histologic Description Scattered multinucleated giant cells

35 Spleen Morphologic Diagnosis

36 Spleen Morphologic Diagnosis Splenitis, granulomatous, multifocal to coalescing, chronic, marked

37 Spleen Acid-fast stain Etiology and Disease Name

38 Spleen Acid-fast stain Etiology and Disease Name Etiology: Mycobacterium avium Disease Name: Avian tuberculosis

39 Case #2 Histologic Description (summary): Scattered throughout the spleen are discrete foci of necrosis surrounded by infiltrates of epithelioid macrophages and multinucleated giant cells admixed with fewer lymphocytes and plasma cells Acid-fast bacilli are present within the lesion Morphologic Diagnosis: Splenitis, granulomatous, multifocal to coalescing, chronic, marked, with intralesional acid-fast bacilli Etiology and Disease Name: Mycobacterium avium Avian tuberculosis

40 Case #2 Avian Tuberculosis Mycobacterium avium complex (serotypes 1, 2 and 3) Can infect an extensive range of species In birds usually chickens, captive wild birds and turkeys Free range farming systems and keeping breeders for several years are conducive to the spread of this disease. Main sources of infection are infected individuals and the contaminated environment (water and soil) Affects multiple organs Granulomatous osteomyelitis and hepatitis

41 Case #3 Signalment: 9 yr-old MC cat History: Cat had been anorexic and was beginning to lose weight. On physical exam the cat was dehydrated. Abdominal palpation revealed enlarged irregular kidneys. Blood chemistry revealed elevated renal enzymes (urea, creatinine).

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43 Gross Description Marked enlargement of the kidneys Nodular/irregular capsular surface

44 Gross Description

45 Gross Description On cut surface, there are multifocal to coalescing, white, round to irregular masses scattered throughout both of the kidneys

46 Morphologic Diagnosis

47 Morphologic Diagnosis Multiple renal masses, probable malignant neoplasia

48 Need Histology! Feline Infectious Peritonitis (Pyogranulomatous nephritis) Compare previous slides with this case of multifocal granulomatous nephritis due to FIP. These lesions can easily be mistaken for renal lymphoma! Two main differentials for this lesion in cats: Lymphoma and FIP Renal lymphoma

49 Histologic Description

50 Histologic Description At low power, we can appreciate a nodule within the tissue (kidney) that looks more blue than normal suggests an increase in the cellularity of the tissue

51 Histologic Description

52 Histologic Description Description: Densely cellular sheet-like infiltrates efface the normal renal architecture leaving few remaining glomeruli

53 At 40x

54 Histologic Description

55 Histologic Description These cells have distinct cell margins, scant eosinophilic cytoplasm, and round nuclei with stippled chromatin and prominent nucleoli. Mitoses are present.

56 Case #3 Histologic Description (summary): In this section of kidney, most of the normal architecture has been effaced by dense sheet-like cellular infiltrates consisting of large numbers of neoplastic round cells. These neoplastic round cells have small amounts of well-delineated pale acidophilic cytoplasm. The nuclei are round to slightly ovoid with stippled chromatin and distinct nucleoli. Morphologic Diagnosis:

57 Case #3 Histologic Description (summary): In this section of kidney, most of the normal architecture has been effaced by dense sheet-like cellular infiltrates consisting of large numbers of neoplastic round cells. These neoplastic round cells have small amounts of well-delineated pale acidophilic cytoplasm. The nuclei are round to slightly ovoid with stippled chromatin and distinct nucleoli. Morphologic Diagnosis: Renal lymphoma Comments: Lymphoma is the most common renal tumor in the cat. It may cause kidney deficiency/failure by destroying parenchyma or by obstructing urine outflow

58 Questions?