Cases for Self-Study (from Duke-NUS)

Case X
A 36-year old woman presented to her general practitioner with fatigue and lethargy. The doctor noticed that she was pale and ordered a number of laboratory investigations. The blood film was reviewed.

1. Which of the following is CORRECT regarding megaloblastic anemia?
   1. Megaloblasts are large circulating cells
   2. The commonest causes of megaloblastic anemia are folate deficiency and Vitamin B12 deficiency
   3. Vitamin B12 deficiency is usually due to inadequate dietary intake
   4. Folate deficiency is usually due to malabsorption

   ANSWER

2. Which of the following statements is CORRECT regarding iron deficiency anemia?
   1. Lack of iron interrupts the final stage of globin synthesis.
   2. Inadequate dietary intake of iron is the commonest cause of iron deficiency.
   3. All patients with iron deficiency anemia should have investigation of their gastrointestinal tract.
   4. The blood film shows a microcytic hypochromic picture.

   ANSWER

    

Case BB
You are the general practitioner in Durham and a 5-year old boy whose parents have recently immigrated from northern Africa  is brought in to see you by his mother. She said the child was born without complications but became lethargic, failed to thrive and required regular blood transfusions.

Hb: 3.2 g/dl (normal 14-17)
Hct: 30%
MCV: 630.1 cubic microns (normal 80-90)
MCH: 20.4 picograms/cell (normal 27 to 31)
Hemoglobin electrophoresis
HbA1: Decreased
HbF: Increased
HbA2: Increased

1. The MOST LIKELY diagnosis is:
   1. Hereditary spherocytosis
   2. Hereditary ovalocytosis
   3. Beta thalassemia
   4. Alpha thalassemia
   5. Autoimmune hemolytic anemia

   ANSWER

   
   
2. Which of the following statements is CORRECT regarding inherited hemolytic anemias?
   1. A raised reticulocyte count with numerous spherocytes on the blood film is diagnostic of hereditary spherocytosis.
   2. Most people with glucose 6 phosphate dehydrogenase deficiency have a mild asymptomatic anemia.
   3. Sickle cell disease is diagnosed by a positive sickle cell solubility test.
   4. Anemia in thalassemia is a result of ineffective erythropoiesis and hemolysis.

   ANSWER

    

Case CC
A 26-year old African American was admitted for appendicitis. A routine complete blood count performed as part of the pre-op workout revealed a low hemoglobin level. A peripheral blood film examination was ordered. There a few sickle cells present.

1. Concerning this disease:
   1. It is due to a point mutation of the alpha-globin chain resulting in substitution of valine for glutamic acid
   2. HbS molecules undergo aggregation and depolymerisation in deoxygenated states
   3. Autosplenectomy may be a feature
   4. Loss of adhesion molecules in sickle cells lead to sludging of red cells within blood vessels and greater tendency to be arrested in the microvasculature.

   ANSWER

    

Case 7
This 35-year old woman presented with multiple petechiae and small bruises over the shins.

1. Which of the following conditions may be responsible?
   1. Henoch-Scholein purpura
   2. Immune thrombocytopenia purpura
   3. Hypersensitivity/Leukocytoclastic vasculitis
   4. ALL of the above
   5. NONE of the above

   ANSWER

    

Case AV
This 25-year old man was referred by his GP for tiredness and lethargy over the past 2 months. Recently, he also noticed bruising over his knees and elbows but he did not remember any history of trauma. A blood film is obtained which shows very numerous white cells with large nuclei and moderate cytoplasm. Some of the nuclei are kidney bean shaped. The cytoplasm of these cells contain granules.

1. What is the MOST LIKELY diagnosis?
   1. Acute lymphoblastic leukemia
   2. Acute myeloid leukemia
   3. Chronic lymphocytic leukemia
   4. Chronic myeloid leukemia
   5. Myelodysplastic syndrome

   ANSWER

2. Which of the following statements is TRUE?
   1. Chronic myeloid leukemia is a neoplasm characterized by clonal proliferation of the neutrophils
   2. Acute myeloid leukemia with t (8; 21) translocation has a dismal prognosis
   3. Chronic lymphocytic leukemia has the same phenotype as small lymphocytic lymphoma
   4. Acute lymphoblastic leukemia with the Philadelphia chromosome has a good prognosis

   ANSWER

    

Case QQ
A 23 year old man presented with a lump in the neck for 3 weeks. He is otherwise asymptomatic and a lymph node biopsy is performed. The biopsy showed a mixture of cells; some smaller mononuclear cells with pleomorphic nuclei and some larger "popcorn" cells. There were a few eosinophils. CD20 was strongly positive in the smaller cells

1. What is the MOST LIKELY diagnosis?
   1. Classic Hodgkin lymphoma
   2. Lymphocyte predominant Hodgkin lymphoma
   3. Lymphocyte rich Hodgkin lymphoma
   4. Lymphocyte depleted Hodgkin lymphoma

   ANSWER

2. Concerning Lymphocyte predominant Hodgkin lymphoma:
   1. This is a form of classic Hodgkin lymphoma with a lot of lymphocytes
   2. This is the same disease as lymphocyte-rich Hodgkin lymphoma
   3. Reed-Sternberg cells are seen in this lymphoma
   4. This lymphoma is associated with progressive transformation of germinal centers
   5. This is derived from post-germinal B-cells with crippled immunoglobulin production apparatus

   ANSWER

    

Case PQ
A 34-year old woman presented with a neck lump for 2 months. She was otherwise well.
A biopsy is obtained which shows effacement of nodal architecture by numerous crowded follicles. Neoplastic cells comprise centrocytes with cleaved or twisted nuclei and small/inconspicuous nucleoli and centroblasts with rounder, larger nuclei and a few prominent nucleoli attached to nuclear membrane. The predominant population is centrocytes in this case.

1. What is the MOST LIKELY diagnosis?
   1. Mantle cell lymphoma
   2. Follicular lymphoma
   3. Small lymphocytic lymphoma
   4. Nodal marginal zone lymphoma
   5. Diffuse large B-cell lymphoma

   ANSWER

2. Which of the following statement is TRUE of this neoplasm?
   1. Arises from immunologically naïve B-cells with unmutated immunoglobulin genes
   2. Generally behaves in an aggressive fashion
   3. Usually presents as nodal disease
   4. Usually presents with bone marrow involvement
   5. Usually produces an IgM paraprotein

   ANSWER

    

Case EB
32-year old female presented with a mass in the neck. Clinical examination revealed a thyroid nodule about 3 cm in diameter which moves with swallowing.

1. Which of the following statements is TRUE?
   1. Variants of follicular carcinoma include the tall cell variant, diffuse sclerosing variant and hyalinizing trabecular adenoma
   2. Papillary thyroid carcinoma shows a propensity for hematogenous spread
   3. The incidence of papillary carcinoma is increased in areas with dietary iodine deficiency
   4. Secretion of calcitonin is a typical feature of follicular carcinoma
   5. Capsular and vascular invasion distinguish follicular carcinoma from follicular adenoma

   ANSWER

    

Case EC
50 year old woman presents with a neck lump. Surgical exploration shows a solitary, well-circumscribed left thyroid nodule 3 cm in diameter. The left lobe of thyroid was resected. The pathology registrar had submitted two slices (each 5mm thick) of the thyroid nodule for microscopic examination. Histology of the nodule shows sheets and crowded follicles without evidence of ground glass nuclei, nuclear pseudoinclusins, multinucleated giant cells, eosinophilic ‘gummy’ colloid or psammoma bodies.

1. What will you do next?
   1. Ask the surgeon to look for an enlarged lymph node and remove the other thyroid lobe
   2. Suggest a thyroid scan to look for metastases
   3. Sample the entire tumor-capsule-thyroid interface
   4. Suggest a total thyroidectomy followed by administration of radioactive iodine
   5. Ask the clinician to check the serum calcium level

   ANSWER

2. Well differentiated follicular carcinoma of the thyroid is differentiated from follicular adenoma of the thyroid by which of the following features?
   1. Hurthle cell change
   2. Small follicles lined by tall cuboidal to columnar cells
   3. Increased mitosis
   4. Vascular invasion within tumor
   5. Extra capsular tumor invasion

   ANSWER

    

Case EE
A 70 year old female is referred to you by the dialysis nurse because she felt bony lumps in patient's arms. Examination reveals hypocalcaemia and lumps in the neck.

1. Which of the following disorder is the MOST LIKELY cause of this patient’s enlarged parathyroid glands?
   1. Primary hyperplasia
   2. Parathyroid adenoma
   3. Chronic renal failure
   4. Parathyroid carcinoma
   5. Lung carcinoma

   ANSWER

    

Case EA
A 33-year old woman visits the office of her family medicine physician. Her chief complaint is nervousness. She describes her nervousness as increasing over the past 6 weeks. She says that her children and husband describe her as atypically ‘easy to anger’. She says that she now easily loses her temper and often cries for little or no apparent reason, and she has developed a tremor in her right arm. She has lost 22 lb since her last office visit 9 months ago and indicates that she has not changed her diet. She describes herself as always ‘hot’. You observe that her eyes protrude and appear red and inflamed, and she describes her eyes as feeling ‘dry’. Your examination reveals asthenia, tachycardia, and pretibial myxedema.

1. Which of the following types of auto antibodies is MOST SPECIFIC for this individual disease?
   1. Antimicrosomal antibodies
   2. Antithyroglobulin antibodies
   3. Antithyroid peroxidase antibodies
   4. TSH receptor blocking antibodies
   5. TSH receptor stimulating antibodies

   ANSWER

    

Case BA
23-year old woman noticed a 2-cm mobile lump in her left breast

1. What is the MOST LIKELY diagnosis?
   1. Fibrocystic change
   2. Fibroadenoma
   3. Phyllodes tumor
   4. Pseudoangiomatous stromal hyperplasia

   ANSWER

2. Which of the following statement is TRUE?
   1. Fibroadenomas are fibroepithelial lesions characterized by stromal overgrowth, hypercellularity, increased mitoses and nuclear pleomorphism
   2. Phyllodes tumors are always much larger than fibroadenomas
   3. Angiosarcoma of the breast may arise spontaneously or as a complication of radiotherapy
   4. Pseudoangiomatous hyperplasia is characterized by foci of rhabdomyosarcomatous or liposarcomatous differentiation

   ANSWER

    

Case BB
A 42-year old woman presented with lumpiness in her right breast. She has been worried about the possibility of breast cancer as her mother had died from it. A biopsy was performed.

1. What is the MOST LIKELY diagnosis?
   1. Fibrocystic change
   2. Fibroadenoma
   3. Phyllodes tumor
   4. Pseudoangiomatous stromal hyperplasia

   ANSWER

2. Which of the following is NOT a component of fibrocystic change?
   1. Pseudoangiomatous stromal hyperplasia
   2. Adenosis
   3. Duct ectasia
   4. Intraductal papilloma
   5. Epithelial hyperplasia

   ANSWER

    

Case BC
45-year old woman noted to have linear calcifications in the right breast on mammographic screening.

1. What is the MOST LIKELY diagnosis?
   1. Atypical ductal hyperplasia
   2. Low grade ductal carcinoma in situ
   3. High grade ductal carcinoma in situ
   4. Lobular carcinoma in situ

   ANSWER

2. Which of the following is associated with 4-5 times relative risk of developing breast cancer?
   1. Ductal epithelial hyperplasia without atypia
   2. Atypical ductal hyperplasia
   3. Ductal carcinoma in situ, low grade
   4. Ductal carcinoma in situ, high grade
   5. Lobular carcinoma in situ

   ANSWER

    

Case BD
A 53-year old woman presented with a 3-cm mass in the left breast. Bilateral masses were noted on palpation.

1. What is the MOST LIKELY diagnosis?
   1. Infiltrating ductal carcinoma
   2. Infiltrating lobular carcinoma
   3. Medullary carcinoma
   4. Colloid (mucinous) carcinoma
   5. Tubular carcinoma

   ANSWER

2. Concerning this diagnosis, which of the following is TRUE?
   1. Well and moderately differentiated examples tend to be negative for estrogen and progesterone receptors
   2. Her2/neu expression is common
   3. Appear as infiltrating cords of neoplastic cells within a desmoplastic stroma
   4. Most cases show amplification of 16q22.1 that encodes E-cadherin and beta-catenin
   5. Often associated with high grade ductal carcinoma in situ

   ANSWER

    

Case SA
40-year old male presents with a swelling in the knee. The patient says that the pain is severe and he gets fever during the night. On examination, the knee is swollen and its shows effusion. The joint is moderately tender. X-ray shows lytic lesions in the lower femur. Both the active and passive movements of the joint are restricted and painful. A biopsy was taken and it shows epithelioid cell granuloma with Langhans giant cells. Ziehl Nielsen stain on the drained effusion shows red beaded bacilli.

1. The MOST LIKELY diagnosis in this case is
   1. Pyogenic osteomyelitis
   2. Tuberculous osteomyelitis
   3. Ewing sarcoma
   4. Sclerosing osteomyelitis of Garre
   5. Myositis ossificans

   ANSWER

    

Case SD
An 18-year old female presents with swelling in the right elbow joint. She noticed the swelling 6 months ago. It has progressed slowly but recently it has become painful. On examination, her hand movements are restricted. The radiological examination shows an eccentric expansion of the proximal part of the radius with erosion and destruction of the cortex and a small peripheral area of periosteal new bone formation. The curettage from the swelling is examined histologically. It shows large spaces filled with blood and lined by cuboidal cells. The septa that separate these cystic spaces contain a row of osteoclast-type giant cells, blood vessels and foci of osteoid and bone.

1. The MOST LIKELY diagnosis is:
   1. Aneurysmal bone cyst
   2. Simple cyst
   3. Ganglion
   4. Synovial cyst
   5. Telangiectatic osteosarcoma

   ANSWER

    

Case QW
A 55-year-old generally healthy man has had episodes of pain and swelling of the right first metatarso pharyngeal joint for the past year. These flare-ups usually occur after consumption of alcohol, typically port wine. On physical examination, there is exquisite tenderness with swelling and erythema of the right first MP joint. A joint aspiration is performed, and laboratory studies of the fluid showed needle-shaped crystals and many neutrophils in a small amount of fluid.

1. Which of the following laboratory findings is MOST LIKELY to be reported in this man?
   1. Increased serum parathyroid hormone level
   2. Elevated serum urea nitrogen level
   3. Hyperuricemia
   4. Markedly elevated levels of serum transaminase
   5. Elevated rheumatoid factor titer

   ANSWER

2. In this disease, deposition of crystals of which of the following kind occurs?
   1. Calcium pyrophosphate crystals
   2. Monosodium urate
   3. Calcium magnesium phosphate
   4. Calcium carbonate
   5. Steroids

   ANSWER

    

Case WR
A 24-year-old man has returned from a camping trip and presents to the primary care physician with a 2-day history of skin rash on his back. He also notes pain in his joints, feeling tired and uneasy all the time. Vital signs are normal. Examination reveals an erythematous, expanding lesion with concentric circles.

1. What is the MOST LIKELY diagnosis (short answer)?

   ANSWER

2. Which of the following is a long-term complication of the condition if left untreated?
   1. Endocarditis
   2. Myocarditis
   3. Restrictive cardiomyopathy
   4. Uveitis
   5. Endarteritis obliterans

   ANSWER

    

Case SC
A 31-year old male presents to your office with painless swelling of the right knee. X-ray studies show significant joint effusion and nodular thickening of the synovium.

1. The MOST LIKELY diagnosis is:
   1. Chondrosarcoma
   2. Giant cell tumor
   3. Osteosarcoma
   4. Pigmented villonodular synovitis
   5. Synovial sarcoma

   ANSWER

    

Case SB
A 26-year old female with a past history of rheumatoid arthritis, presents with a history of swelling in the popliteal region. The swelling is painless and measures 4cm in diameter. The swelling is cystic and excised. On examination, the cyst wall is lined by proliferating synovial cells and it shows inflammatory infiltrates consisting of lymphocytes and plasma cells.

1. The MOST LIKELY diagnosis in this case is:
   1. Aneurysmal bone cyst
   2. Simple cyst
   3. Ganglion
   4. Synovial cyst
   5. Telangiectatic osteosarcoma

   ANSWER

    

Case SE
Following a fall on a basketball court, a 20-year-old man develops a swollen and painful upper arm. Over the next several weeks, the involved area becomes more circumscribed and firm and then later evolves to a painless, hard, well-demarcated mass.

1. What is the MOST LIKELY diagnosis?
   1. Osteoid osteoma
   2. Osteosarcoma
   3. Myositis ossificans
   4. Aneurysmal bone cyst
   5. Fibrous dysplasia

   ANSWER

2. X-ray of the arm at this point would MOST LIKELY demonstrate which of the following?
   1. Benign-appearing bony outgrowths from the humerus
   2. Dislocation of the shoulder
   3. Flocculent radiodensities surrounding a radiolucent center
   4. Healing fracture
   5. Malignant-appearing bony outgrowths from the humerus

   ANSWER

    

Case WA
A 32-year-old female complains of a slowly growing swelling in the elbow. She noticed it a few months ago, but the swelling has been gradually increasing in size. On examination, the swelling is subcutaneous and is 2 cm in diameter. She underwent surgery subsequently for the same. Grossly, the swelling is not encapsulated and is gray white.

1. The MOST LIKELY diagnosis in this case is:
   1. Neurofibroma
   2. Benign fibrous histiocytoma
   3. Malignant peripheral nerve sheath tumor
   4. Neurilemmoma
   5. Lipoma

   ANSWER

    

Case WB
A 46-year-old man presents with a mass in the left thigh. He is a known case of Recklinghausen's disease and had a swelling in the same region for many years. However, there has been a sudden increase in the size of this swelling. On examination, this swelling measures 15cm in diameter and involves the soft tissue. It is not attached to the underlying bone. A biopsy taken from the swelling shows uniform spindled cells with wavy nuclei arranged in sweeping fascicles with areas showing myxoid changes. Some cells are pleomorphic with occasional bizarre cells. Frequent mitoses are noted. The tumor is positive for S100 protein.

1. The MOST LIKELY diagnosis in this case is:
   1. Neurofibroma
   2. Lipoma
   3. Neurilemmoma
   4. Benign fibrous histiocytoma
   5. Malignant peripheral nerve sheath tumor

   ANSWER

    

Case WC
An 18-year old female presents with a swelling in the nape of the neck. She noticed it a few months back but it has been gradually increasing in size. Surgically excised specimen of the swelling reveals an encapsulated tumor. Microscopically, the cells are arranged in 2 patterns. Some areas are cellular, show spindle cells with wavy nuclei arranged in a palisading fashion, and in other others, the cells are separated by abundant edematous fluid.

1. The MOST LIKELY diagnosis in this case is:
   1. Neurofibroma
   2. Lipoma
   3. Schwannoma
   4. Benign fibrous histiocytoma
   5. Malignant peripheral nerve sheath tumor

   ANSWER

    

Case AA
A 2-year-old girl is seen by her pediatrician because of redness, scaling, and crusting of the skin of the elbows, hands, and legs. The parents tell him that the lesions started a week ago with papules and blisters that were very itchy. They also relate that this is not the first time that their child has had these symptoms. Nearly a year ago, she had identical abnormalities that were than seen by a family doctor. The mother relates that she suffered as a child from identical lesions as her daughter has now. The father does not recall such abnormalities during his childhood. Laboratory investigations of the child show a slightly elevated level of IgE in her plasma, and slightly decreased numbers of suppressor T cells. The parents have read about atopic eczema on the internet and learned that these children are prone to develop bacterial and viral infections that sometimes are life threatening; this is the main reason why they wanted to see a specialist. A number of tests are performed to detect the cause of this hypersensitivity reaction.

1. What is the MOST LIKELY diagnosis?
   1. Contact dermatitis
   2. Atopic eczema
   3. Seborrheic dermatitis
   4. Photosensitive dermatitis

   ANSWER

2. Which of the following histological features are NOT seen in eczema/dermatitis?
   1. Spongiosis
   2. Acanthosis
   3. Perivascular inflammatory cells
   4. Acantholysis
   5. Intraepidermal vesicle

   ANSWER

    

Case AB
An 18-year-old man first discovered an itchy, scaling, red papule on the skin of an elbow. In the course of several months, the lesions also appeared on the other elbow, the knees and the scalp. At this time, he saw a dermatologist. When the scale was lifted from a plaque, multiple, minute bleeding points became visible. A biopsy was performed at an edge of a lesion, and a diagnosis was made. Subsequently, a therapy was started that alleviated the symptoms but did not result in a complete remission of the disease. In the next years, the lesions were progressive, and also other parts of the skin were involved, such as the abdomen and the intergluteal cleft. While vacationing in a sunny area with a beach, the patient found out that swimming under those circumstances had a beneficial effect on the extent of his disease. After 20 years with this disease, he also developed arthritis.

1. What is the MOST LIKELY diagnosis?
   1. Lichen simplex chronicus
   2. Chronic eczema
   3. Psoriasis
   4. Mycosis fungoides
   5. Tinea corporis

   ANSWER

    

Case AC
A 53-year old man presents withh dandruff and itchy rash on the face. You notice a papular rash with greasy scales over the forehead and nasolabial folds. You performed a swab from the area and found yeast organisms.

1. The MOST LIKELY diagnosis is:
   1. Contact dermatitis
   2. Atopic eczema
   3. Seborrheic dermatitis
   4. Photosensitive dermatitis

   ANSWER

    

Case SK
A 55-year-old man sees his doctor because of a firm, light brown papule on his back. The lesion is round, has a diameter of 14 mm, and surfaces 3 mm above the surrounding skin level. The lesion appearance has not changed during the past year. His neighbor was diagnosed with melanoma recently. Now he worries that he might have a malignant melanoma as well. There is no bleeding, itching, or pain. The edges of the lesion are regular.

1. What is the MOST LIKELY diagnosis?
   1. Viral wart (verruca vulgaris)
   2. Basal cell carcinoma
   3. Seborrhoeic keratosis
   4. Melanoma
   5. Eccrine poroma

   ANSWER

    

Case M
A 51-year-old man sees his physician because of growth and change in color of an abdominal mole that, according to his statement, has been present since his birth. The mole always had an oval shape with an even, brownish pigmentation. Recently the patient noticed some changes at the edges of the mole. The shape has become irregular recently and some areas show shades of black and brown colors. He denies pain or itching. This is the first time that he has seen a physician for this type of complaint. He has no family history of malignant melanoma.

1. What is the MOST LIKELY diagnosis?
   1. Paget’s disease of the skin
   2. Melanoma
   3. Dysplastic nevus
   4. Intradermal nevus

   ANSWER

2. Which of the following is the MOST IMPORTANT prognostic feature in this tumor?
   1. Age of patient
   2. Smoking history
   3. Alcohol history
   4. Thickness of tumor
   5. Site of tumor

   ANSWER

3. The following are recognized histologic types of melanoma EXCEPT:
   1. Superficially spreading melanoma
   2. Acral lentinginous melanoma
   3. Nodular melanoma
   4. Melanocytoma
   5. Lentigo maligna

   ANSWER