Surgical Pathology Unknown Conference

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Surgical Pathology Unknown Conference

• 11 June 2007
• Michael L. Wilson, M.D.

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Case 1

• A 26-Year-Old Female With Good Prenatal Care
  Presents With Severe Pre-Eclampsia. The Delivery
  is Unremarkable With a Viable Fetus and High
  Apgar Scores.

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Case 1

• What Lesions in the Placenta Should the
  Pathologist Look for in Cases Described as
  Pregnancy-Induced Hypertension, Pre-Eclampsia, or
  Eclampsia?
• What are the Diagnostic Criteria for These
  Lesions?
• How do the Lesions Evolve Over Time?
• Are There Any Mimics?
• Can Those Lesions be Associated with Any Other
  Processes?

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Case 1

• Diagnosis Atherosis (Decidual Vasculopathy)

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Case 1

• Atherosis (Decidual Vasculopathy)
• Clinical Importance
• Associated With Hypertension
• Also Seen With Intra-Uterine Growth Retardation

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Case 1

• Atherosis (Decidual Vasculopathy)
• Histopathology
• Fibrinoid Necrosis of Decidual Vessels
• Mononuclear Infiltrate
• Subendothelial Foamy Macrophages
• Subendothelial Fat Deposition

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Case 2

• A 37-Year-Old Female Presents Develops Pulmonary
  Tuberculosis and is Treated Until Both Sputum
  Smears and Cultures Become Negative. She Now
  Presents With a Febrile Illness Sputum Smears
  are Positive for Acid-Fast Bacilli but Cultures
  are Negative. The Patient Subsequently Dies of
  Acute Bronchopneumonia.

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Case 2

• What Information can be Derived From the
  Histopathologic Sections of Lung Regarding the
  Clinical Status of the Patient (i.e., is this
  Active or Successfully Treated Tuberculosis)?
• What is the Role, if Any, of Nucleic Acid
  Amplification Tests in the Diagnosis of this
  Disease?
• What is the Risk of Performing an Autopsy or
  Processing a Lung Resection From this Patient?
  How can That Risk be Minimized?
• What is the Risk of Cutting and Processing the
  Tissues in a Histology Laboratory?

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Case 2

• Diagnosis Pulmonary Tuberculosis

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Case 2

• Pulmonary Tuberculosis
• Mycobacterium tuberculosis Complex
• M. tuberculosis
• M. bovis
• M. africanum
• gt 2 Billion Persons Infected Globally
• 2 Million Deaths Annually

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Case 2

• Pulmonary Tuberculosis
• Treatment Requires Multiple Drugs for Prolonged
  Time
• Multiple Drug-Resistant (MDR) Resistant to INH
  and Rifampin
• Extensively Drug-Resistant (XDR)
• MDR Plus
• Resistance to Fluoroquinolone Plus
• Resistance to One Injectable Drug

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Case 2

• Pulmonary Tuberculosis
• Histopathology
• Classic Necrotizing Granulomata
• Acid-Fast Bacilli at Interface Between
  Necrotic/Viable Tissue
• Insensitive and Non-Specific Test
• Culture
• Sensitive and Specific Test
• 10-14 Days
• Adenosine Deaminase Levels of Fluids
• Nucleic Acid Amplification of Sputum, Fluids, ?
  Tissue

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Case 3

• A 28-Year-Old Female Delivers a Healthy Fetus at
  Term. The Mother had No Prenatal Care, but All
  Screening Tests for Infectious Diseases at the
  Time of Delivery Are Negative.

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Case 3

• Describe the Histopathologic Changes in the
  Placenta.
• What is This Process Called?
• What are the Causes, both Infectious and
  Non-Infectious, of These Changes?
• What Further Workup is Warranted in This Case?

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Case 3

• Diagnosis Villitis of Unknown Etiology (VUE)

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Case 3

• Villitis of Unknown Etiology (VUE)
• Association With Intrauterine Growth Retardation,
  Stillbirths, and Premature Birth
• Perhaps up to 10 of Placentas in Western
  Countries
• Associated With Acute or Chronic Chorioamnionitis
• ? Immune Pathogenesis
• More Important if gt5 of Villi are Involved

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Case 3

• Villitis of Unknown Etiology (VUE)
• Histopathology
• Mononuclear Infiltrate Within Stroma of Chorionic
  Villi
• May be Present Only at Maternal Surface (Basal
  Villi)
• Often More Severe at Maternal Surface (Basal
  Villi)
• Giant Cells

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Case 4

• A 44-Year-Old Male is Involved in a Motor-Vehicle
  Accident and Sustains Extensive Trauma to the
  Right Leg. After a Number of Procedures the
  Patient Develops Non-Union of a Tibial Fracture
  and Osteomyelitis of the Adjacent Tibia. Despite
  Prolonged Therapy, the Leg is Amputated Below the
  Knee. The Section Provided is from the Surgical
  Amputation Margin 12 cm Above the Site of
  Non-Union.

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Case 4

• What are the Histopathologic Changes? What is the
  Diagnosis? What are the Minimal Criteria for
  Making That Diagnosis?
• Should any Special Stains be Performed? If so,
  Which Ones?
• What Does This Finding Mean in Terms of
  Prognosis?
• Should Margins be Evaluated in Limb Amputations
  for Diseases Other Than Tumors?

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Case 4

• Diagnosis Osteomyelitis

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Case 4

• Osteomyelitis
• Infection of Bone, May be Hematogenous, From
  Trauma, or Iatrogenic
• Post Surgical
• Associated with Orthopedic Hardware
• Serious Infection Requires up to 6 Weeks of IV
  Antimicrobial Therapy
• Significance of Osteomyelitis at Surgical
  Amputation Margins has not Been Studied

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Case 4

• Osteomyelitis
• Histopathology
• Diagnosis Based on Combination of Inflammation
  and Presence of Necrotic Bone
• Acute and Chronic Probably a Meaningless
  Distinction
• Granulomatous Variants Exist
• Infectious Mycobacterial or Fungal
• Idiopathic is Non-Infectious

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Case 5

• A 33-Year-Old Female with No Prenatal Care
  Delivers a Healthy Baby at (Estimated) 36-38
  Weeks Gestation. The Mother has No Past Medical
  History of Concern and has had Previous Normal
  Pregnancies and Deliveries.

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Case 5

• One Major Surgical Pathology Textbook States That
  This is not an Infectious Process. Despite That
  Claim, an Immunoperoxidase Stain for Herpes
  simplex virus (HSV) is Performed and is Strongly
  Positive in These Cells.
• What Does This Mean?
• What do you Tell the Clinician?
• Should They Treat the Mother and/or the Baby?

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Case 5

• The Patient is Subsequently Found to Have no
  Known Clinical History of HSV Infection. Does
  This Affect Your Interpretation?
• What if the Mother Does Have a History of HSV
  Infection?
• What Other Tests Could be Performed on Tissue
  Sections? What Tests Could be Performed on Serum
  From the Mother?

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Case 5

• Diagnosis Herpes Simplex Virus (HSV) Deciduitis

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Case 5

• Herpes Simplex Virus Deciduitis
• Uncommon Diagnosis
• Varying Opinions Regarding Clinical Importance
• Arch Pathol Lab Med 19911151141-4

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Case 5

• Herpes Simplex Virus Deciduitis
• Histopathology
• Decidual Cells, Often Endothelial Cells, With
  Nuclear Clearing Similar to Viral Cytopathic
  Effect of HSV Seen in Other Tissues
• Immunoperoxidase Stains Positive for HSV
• ? Role of in situ Hybridization or Other Tests