The document presents 13 image-based questions related to cases from Harrison’s Principles of Internal Medicine, covering various medical conditions including Chédiak-Higashi syndrome, erysipelas, multiple myeloma, mumps, and more. It provides detailed answers and descriptions of symptoms, causes, and diagnostic approaches, along with relevant images and figures from the textbook. Additionally, it discusses related clinical factors, such as complications, diagnostic tests like urine measurements, and specific terms associated with certain diseases.

1. IMAGE BASED
QUESTIONS
( Based on Harrison’s
Principles of Internal
Medicine 21st edition )
DECEMBER 2024

2. Included in this presentation are 13 image based questions
(IBQs) based on the 21st edition of harrison’s Principles of
Internal Medicine.
The figure number / table number in the textbook is mentioned.
The student is requested to read the relevant topic in Harrison’s
to understand the concept better.

3. IBQ 1
Figure 64-10
Which is the
disorder ?

4. ANSWER
Chédiak-Higashi syndrome (CHS)
A rare disease with autosomal recessive inheritance due to defects
in the lysosomal transport protein LYST, encoded by the gene
CHS1 at 1q42. This protein is required for normal packaging and
disbursement of granules.
The granulocytes contain huge cytoplasmic granules formed from
aggregation and fusion of azurophilic and specific granules. Large
abnormal granules are found in other granule-containing cells
throughout the body.

5. IBQ 2 Figure 148-4
The condition
and the
causative
agent is ?

6. ANSWER
ERYSIPELAS
Erysipelas is characterized by a bright red appearance of the involved skin, which forms a
plateau sharply demarcated from surrounding normal skin .
The lesion is warm to the touch, may be tender, and appears shiny and swollen. The skin
often has a peau d’orange texture, which is thought to reflect involvement of superficial
lymphatics; superficial blebs or bullae may form, usually 2–3 days after onset. The lesion
typically develops over a few hours and is associated with fever and chills.
Erysipelas tends to occur on the malar area of the face (often with extension over the
bridge of the nose to the contralateral malar region) or on the lower extremities. After
one episode, recurrence at the same site—sometimes years later—is not uncommon.

7. Classic cases of erysipelas, with typical features, are almost always due
to β-hemolytic streptococci, usually GAS and occasionally group C or
G.
Often, however, the appearance of streptococcal cellulitis is not
sufficiently distinctive to permit a specific diagnosis on clinical grounds.
The anatomic area involved may not be typical for erysipelas, the lesion
may be less intensely red than usual and may fade into surrounding skin,
and/or the patient may appear only mildly ill. In such cases, it is prudent
to broaden the spectrum of empirical antimicrobial therapy to include
other pathogens, particularly S. aureus, that can produce cellulitis with
the same appearance. Staphylococcal infection should be suspected if
cellulitis develops around a wound or an ulcer.

8. IBQ 3 Figure 111-5
The first image is the X ray of the skull , while the second image shows
FDG PET/CT of this condition pre and post treatment. He had long
standing back ache and anemia. Diagnosis ?

9. ANSWER
Multiple myeloma
The skull demonstrates the typical “punched out” lesions
characteristic of multiple myeloma. The lesion represents a
purely osteolytic lesion with little or no osteoblastic activity.
PET/CT shows multiple fluorodeoxyglucose (FDG)-avid lesions in
skeleton (left panel) with their resolution on achieving complete
response (CR)

10. IBQ 4 Figure 207-2
This patient had fever and bilateral
parotid swelling of acute onset , which
resolved with symptomatic measures.
The image before the illness and on
day 3 of illness is shown.
● The likely diagnosis is ?
● The most frequent complications
of this condition ?
● The best prevention measure
against this condition is ?

11. ANSWER
● Mumps
● The most frequent complications of mumps
include orchitis, oophoritis, mastitis,
pancreatitis, hearing loss, meningitis, and
encephalitis. Complications can occur in the
absence of parotitis and are more common
among adults than among children and among
males than among females, likely due to rates of
orchitis.
● Vaccination
Humans are the only
known natural
reservoir for mumps
virus, which is
transmitted through
direct contact with
respiratory droplets
or saliva of an
infected person.

12. IBQ 5 Figure 240-14
The ECG
changes
shown are
related to
which
condition ?

13. ANSWER
HYPERKALEMIA

14. IBQ 6 Figure 72-8
The _______ effect is a
metabolic phenomenon
in which cancer cells
consume large amounts
of glucose and convert it
to lactate, even when
oxygen is present. This
process is known as
"aerobic glycolysis".

15. ANSWER
Warburg effect
In most normal tissues, the vast majority of cells are differentiated and
dedicated to a particular function within the organ in which they reside.
The metabolic needs are mainly for energy and not for building blocks for
new cells. In these tissues, ATP is generated by oxidative phosphorylation
that efficiently generates about 36 molecules of ATP for each molecule of
glucose metabolized. By contrast, proliferative tumor tissues, especially
in the setting of hypoxia, a typical condition within tumors, use aerobic
glycolysis to generate energy for cell survival and generation of building
blocks for new cells.

16. IBQ 7 Figure 228-2
This patient with AIDS had a
CD4 cell count of less than
100 /microL.
He presented with confusion
and seizures.
The MRI image is shown.
Findings & possible etiology ?

17. ANSWER
Toxoplasmosis
Multiple ring enhancing lesions are seen.
Cerebral toxoplasmosis must be differentiated from other
opportunistic infections or tumors in the CNS of AIDS patients.
The differential diagnosis includes herpes simplex encephalitis,
cryptococcal meningitis, progressive multifocal
leukoencephalopathy, and primary CNS lymphoma

18. IBQ 7 Figure 309-2
A. Name the specialized cells in
the thick ascending limb of
the loop of Henle that act as
sensors of solute
concentration and tubular
fluid flow rate. They mediate
tubuloglomerular feedback.
B. Renin is released from
_________within the wall of the
afferent arteriole.

19. ANSWER
a. Macula densa
b. Granular cells ( also called juxtaglomerular cells )

20. IBQ 8 Figure 416-3
This patient on evaluation
was found to have the
enzyme Hepatic
URO-decarboxylase
deficient .
The disease is ?

21. ANSWER
PORPHYRIA CUTANEA TARDA ( PCT )
PCT is the most common of the porphyrias, can be either sporadic (type 1) or familial
(type 2) and can also develop after exposure to halogenated aromatic hydrocarbons.
Hepatic URO-decarboxylase is deficient in all types of PCT, and for clinical
symptoms to manifest, this enzyme deficiency must be substantial (~20% of normal
activity or less).
Blistering skin lesions that appear most commonly on the backs of the hands are
the major clinical feature . These rupture and crust over, leaving areas of atrophy
and scarring. Lesions may also occur on the forearms, face, legs, and feet.

22. IBQ 9
Table 436-1
Identify the
movement
disorders
hidden by the
boxes

23. ANSWER

24. IBQ 10
Figure 84-6
In patients with suspected carcinoid
syndrome , the measurement of
____________ ( hidden by the green box ) ,
a tryptophan metabolite , can be
measured in urine to facilitate the
diagnosis.

25. ANSWER
5 Hydroxy indole acetic acid ( 5 HIAA )
Tryptophan is converted to hydroxytryptophan by tryptophan
hydroxylase within the tumor cell and, subsequently, to serotonin
(5-HT). Serotonin is subsequently converted to 5-hydroxyindole
acetic acid (5-HIAA), which can be measured in a 24-h urine
collection and can facilitate the diagnosis of carcinoid syndrome.

26. IBQ 11 Figure 234-1
These are the
eggs of ?

27. ANSWER
Schistosoma haematobium
The schistosome egg is the only stage of the parasites’ life cycle that
can be detected in humans, either in excreta or in tissue biopsies.
The eggs are large and can easily be distinguished morphologically
from other helminth eggs. S. haematobium eggs are ~140 mm long,
with a terminal spine.

28. IBQ 12 Figure 311-4
The image of the arm of a CKD patient on
HD.
He was non adherent to dietary phosphate
restriction or the use of phosphate binders.
He was chronically hyperphosphatemic.
The mass seen in the image was painful and
slowly enlarging. It was extensively calcified.
What is this called ?

29. ANSWER
Tumoral calcinosis
● Tumor-like deposits of calcium hydroxyapatite in soft tissue surrounding
major joints
● Can be primary (familial or sporadic) or secondary (tumoral calcinosis-like
lesions)
● Secondary form is associated with various predisposing conditions,
including chronic renal failure (typically associated with secondary
hyperparathyroidism), primary hyperparathyroidism, systemic sclerosis,
scleroderma, dermatomyositis, sarcoidosis, osteoarthritis and congenital
deformities

30. IBQ 13
Figure 367 - 4
What is the term given
to this complex of
cutaneous lesions seen
in sarcoidosis ?

31. ANSWER
Lupus pernio
● Lupus pernio is a cutaneous manifestation of sarcoidosis
● Presents as a violaceous lesion or shiny nodules over the head and neck but is
predominantly localized to the nose, cheeks, and ears
● Can present either as an isolated skin lesion or it can be an early manifestation of
systemic sarcoidosis.
● Often a predictor of systemic sarcoidosis, which warrants thorough workup. Patients
with lupus pernio have a higher risk for pulmonary disease.