Normal Lab Values

Nerve, Muscle, & Eye - Readings from Robbins Basic Pathol, 10th ed. (equivalent readings in 9th ed. in parentheses)

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pp 835 - 840 (9e:797-808)
pp 840 - 845 (9e:797-808)
     
 

pp 846 - 847

pp 1319 - 1342 ("big" Robbins, 10e) (9e:1319-1342)

     

Website cases:

 

 

 

CASE NUMBER 221
(no virtual slide for this case)

Clinical History:  A 55-year-old man underwent total nephrectomy for renal cell carcinoma and subsequently received adjuvant chemotherapy. While on chemotherapy, he became leukopenic and thrombocytopenic. He presented to his oncologist with a 3-day history of a rash on his left side.

 

221-1. What is the differential diagnosis?

ANSWER

Image Gallery:

(Summary of Gross Findings)
There is a band-like papulovesicular rash with lesions averaging 3-5 mm in size.
(Summary of Microscopic Findings)
The epidermis shows spongiosis, vesicle formation, necrosis and ulceration. The epidermal cells have degrees of ballooning degeneration. Many intranuclear eosinophilic inclusion bodies are seen in these cells. Many keratinocytes within the vesicle also have multiple nuclei with nuclear "molding" and marginated chromatin. The upper dermis beneath a vesicle shows necrosis with little or no inflammatory reaction.
(Review Skin Histology)
Norm No. 15 Skin
[ImageScope] [WebScope]

Skin consists of keratinizing stratified squamous epithelium. The keratin layer is eosinophilic. Nuclei are not present. Beneath the keratin layer is a layer of flat epithelial cells with small pyknotic nuclei. Cells are regular and not crowded. These keratinocytes rest upon a layer of basal epithelium and a thin basement membrane. Beneath the epidermis is the dermis which consists of loose connective tissue. Within the dermis are sweat and sebaceous glands. Some slides contain hair follicles. There is no inflammation. The blood vessels are patent and do not contain thromboemboli.

 

Click here for a video debrief of the pathology findings presented in this case.

 

221-2. Which of the following is the etiologic agent for this disease?

  1. Cytomegalovirus
  2. Herpes simplex virus-2
  3. Human papilloma virus, type 6
  4. Poliovirus
  5. Varicella-zoster virus

ANSWER

 

221-3. Where is latent infection established following primary infection?

  1. Dorsal root ganglia
  2. Motor axons
  3. Neuromuscular junction
  4. Peripheral sensory nerves
  5. Skeletal muscle

ANSWER

 

221-4. Which of the following is a rare complication that can be seen in this disease?

  1. B-cell lymphoma
  2. Facial hemiparesis
  3. Myocarditis
  4. Toxic shock syndrome
  5. Vegetations on heart valves

ANSWER

 

CASE NUMBER 544
(no virtual slide for this case)

Clinical History:  A 5-year-old boy is brought to the pediatrician because his parents notice that he walks on his toes and has difficulty climbing stairs. They state that he did not begin walking until he was 18 months old. Physical exam reveals bilaterally enlarged calves. A muscle biopsy is performed.

 

544-1. What is the differential diagnosis?

ANSWER

 

Image Gallery:

 
(Summary of Microscopic Findings)

The low power view (left) shows fatty replacement of muscle fibers and hypertrophy and atrophy of fibers. The higher power view (right) shows marked fibrosis, fiber splitting, degeneration/myophagocytosis, and regeneration (internal nuclei).

(Review Skeletal Muscle Histology)
Norm No. 18 Skeletal muscle
[ImageScope] [WebScope]

Skeletal muscle fibers have striations which are easily seen on the longitudinal section. Nuclei are located at the periphery of normal striated muscle fibers.

 

 

Clinical History, part 2 (click here to move on to part 2)

 

 

CASE NUMBER 523- slide courtesy of UMich
[ImageScope] [WebScope]

Clinical History:  An 18-year-old man presents for his Army physical. The doctor notices multiple skin lesions distributed evenly across his body and irregular areas of hyperpigmentation. The patient states that he has had these lesions his entire life but that they had never bothered him. One of the lesions is biopsied.

 

523-1. What is the differential diagnosis?

ANSWER

Image Gallery:

(Summary of Clinical Findings)
There are multiple soft, fleshy, pedunculated lesions present. In addition, there is a focus of hyperpigmentation consistent with a café au lait spot.
(Summary of Microscopic Findings)
There is an infiltrative, non-circumscribed lesion present in the dermis that is composed of wavy or buckled spindle cells distributed amidst ropy collagen bundles and myxoid stroma. Mitotic activity, necrosis and cryptologic atypia are not seen.
(Review Skin Histology)
Norm No. 15 Skin
[ImageScope] [WebScope]

Skin consists of keratinizing stratified squamous epithelium. The keratin layer is eosinophilic. Nuclei are not present. Beneath the keratin layer is a layer of flat epithelial cells with small pyknotic nuclei. Cells are regular and not crowded. These keratinocytes rest upon a layer of basal epithelium and a thin basement membrane. Beneath the epidermis is the dermis which consists of loose connective tissue. Within the dermis are sweat and sebaceous glands. Some slides contain hair follicles. There is no inflammation. The blood vessels are patent and do not contain thromboemboli.

 

Click here for a video debrief of the pathology findings presented in this case.

 

523-2. A mutation in a gene encoding which of the following is most commonly observed in patients with this disease?

  1. Dystrophin
  2. E-cadherin
  3. Merlin
  4. Neurofibromin
  5. Tuberin

ANSWER

 

523-3. Identification of which of the following is highly suggestive of this diagnosis?

  1. Hemangioblastoma
  2. Meningioma
  3. Plexiform neurofibroma
  4. Solitary cutaneous neurofibroma
  5. Vestibular schwannoma

ANSWER

 

Clinical History (continued): Ten years later, the patient presents to his primary care physician with a 3-week history of “burning” and “shooting” nerve pain in his right arm.  MRI revealed a 5 cm mass within the brachial plexus. The mass was excised.

 

523-4. What is the differential diagnosis?

ANSWER

 

Image Gallery:

[ImageScope] [WebScope] - slide courtesy of UMich

(Summary of Microscopic Findings)
Residual neurofibroma is present on the superior aspect of the tissue. The remaining tissue shows fascicular architecture, cytologic atypia, hypercellularity and scattered mitotic figures. There is focal necrosis and vascular invasion.

 

523-5. Which of the following is the life time risk for developing this type of tumor in a patient with this disease?

  1. <1%
  2. 1 – 10%
  3. 21 - 30%
  4. 51 - 60%
  5. >90%

ANSWER

 

 

CASE NUMBER 390- slide courtesy of UMich
[ImageScope] [WebScope]

Clinical History:A 58-year-old man presented to his primary care physician with a 3-month history of blurred vision in his left eye. Previously, he had 20-20 vision in both eyes and had not seen an ophthalmologist since he was in college.

A fundoscopic exam revealed a pigmented lesion near the fovea in the left eye. Ultrasonographic examination confirmed a diameter of 10 mm with a thickness of 3.5 mm.  Following discussion, treatment options including radiation therapy and enucleation  were discussed, but the patient declined. Ten months later, he presented with worsening vision and eye pain and fundoscopic exam revealed that the lesion had progressed. At this point, the patient agreed to enucleation.

 

390-1. What is the differential diagnosis?

ANSWER

Image Gallery:

(Summary of Clinical Findings)
There are multiple soft, fleshy, pedunculated lesions present. In addition, there is a focus of hyperpigmentation consistent with a café au lait spot.
(Summary of Microscopic Findings)
There is an infiltrative, non-circumscribed lesion present in the dermis that is composed of wavy or buckled spindle cells distributed amidst ropy collagen bundles and myxoid stroma. Mitotic activity, necrosis and cryptologic atypia are not seen.

 

Click here for a video debrief of the pathology findings presented in this case.

 

390-2. Which oncogene is most commonly mutated in this disease?

  1. BAP1
  2. CFH
  3. GNAQ
  4. RHO
  5. USH2A

ANSWER

 

 

390-3. Which feature is associated with worse prognosis in this disease?

  1. Depth of invasion
  2. Lateral extent of tumor
  3. Origination in the iris
  4. Spindle cell morphology
  5. Ulceration

ANSWER

 

 

390-4. Which of the following is the most common site of metastasis for this tumor?

  1. Bone
  2. Brain
  3. Liver
  4. Lung
  5. Soft tissue

ANSWER

 

 

MUSCLE PATHOLOGY Review Items

Muscle Pathology Key Vocabulary Terms (click here to search any additional terms on Stedman's Online Medical Dictionary)

chromatolysis hypotonia rhabdomyolysis
dermatomyositis myopathy ring fiber
dystrophin myotonia target fiber
dystrophy nemaline rod  type I fiber
fasciculation neuropathy type II fiber
fiber type grouping  ophthalmoplegia Werdnig-Hoffmann disease
floppy infant syndrome pseudohypertrophy

Eye Pathology Key Vocabulary Terms (click here to search any additional terms on Stedman's Online Medical Dictionary)

arcus senilis ectropion ophthalmoplegia
arteriovenous nicking emmetropia otosclerosis
astigmatism entropion papilledema
blepharitis exophthalmos photophobia
blepharochalasis glaucoma phthisis bulbi
blindness hyperopia pinguecula
buphthalmos hypertelorism presbycusis
cataract hyphema presbyopia
chalazion hypopyon proptosis
cherry-red macula iridocyclitis pterygium
cholesteatoma iritis scotoma
coloboma keratic precipitate synechia
cotton-wool spots keratitis uveitis
diabetic retinopathy keratoconus xanthelasma
proliferative retinopathy keratomalacia xerophthalmia
drusen myopia  

PNS: GOALS and LEARNING OBJECTIVES

Goal: Neuromuscular  and Muscular Disorders
Apply knowledge of clinical, anatomic and neuropathologic principles to the diagnosis of neuromuscular and muscular disorders.

  • Objective 1: Amyotrophic Lateral Sclerosis
    Describe the etiology, pathogenesis, and clinical features of amyotrophic lateral sclerosis.
  • Objective 2: Mitochondrial Disorders
    Describe the etiology, pathogenesis, and clinical features of mitochondrial diseases affecting muscle.
  • Objective 3: Muscular Dystrophies
    Compare and contrast the etiology, pathogenesis, and clinical features of the dystrophiopathies.
  • Objective 4: Acquired Disorders of Skeletal Muscle
    Compare and contrast the etiology, pathogenesis, and clinical features of inflammatory myopathies and toxic myopathies.

Goal: Pathology of Peripheral Nerves
Apply knowledge of clinical, anatomic and neuropathologic principles to the diagnosis of neural disorders.

  • Objective 1: Disorders Associated with Peripheral Nerve Injury
    Compare and contrast the peripheral neuropathies in terms of etiology, risk factors, clinical presentation, pathologic findings and natural history.
  • Objective 2: Disorders of the Neuromuscular Junction
    Compare and contrast the disorders of the neuromuscular junction in terms of etiology, risk factors, clinical presentation, pathologic findings and natural history.
  • Objective 3: Peripheral Nerve Sheath Tumors
    Compare and contrast benign and malignant tumors of the peripheral nerve sheath in terms of etiology, genetics, associated syndromes, clinical presentation, pathologic findings and prognostic factors.

 

 

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