Pathology

Question 1

What is the most common histologic finding in a polymorphous low grade adenocarcinoma? Where is it often found?

Answer 1

Indian or single file cell infiltration into surrounding tissues. It is found almost exclusively in the minor salivary galnds.

Question 2

What neoplasms stain positive for S-100?

Answer 2

Nerve lesions. Neurofibromas and Schwannomas clasically stain positive for S-100.

Question 3

What structural protein is stained for in an odontogenic myxoma?

Answer 3

Vimentin

Question 4

What is a symblepharon? What mucous membrane lesion is it seen in?

Answer 4

A symblepharon is a partial or complete adhesion between the palpebral conjunctiva of the eyelid and the bulbar conjunctiva of the eyeball. It is seen in pemphigoid.

Question 5

A granular cell tumor is excised with positive margins. What is the recommended treatment?
A. observation
B. additional resection with frozen sections
C. radiation
D. chemotherapy

Answer 5

A. Observation
Even surgical manipulation will assist with involution of the tumor. This is an uncommon, benign soft tissue neoplasm that usually occurs on the dorsum of the tongue. It is asymptomatic and can be present for years without any changes

Question 6

What is the most common malignancy of the submandibular gland?

Answer 6

Adenoid cystic carcinoma

Question 7

What is the most common type of invasion for adenoid cystic carcinoma?
A. Perineural
B. Vascular
C. Lymphatic
D. Local spread

Answer 7

A. Perineural invasion

Question 8

What is the most common salivary gland malignancy?
A. Adenoid cystic carcinoma
B. Mucoepidermoid carcinoma
C. Polymorphous Low Grade Adenocarcinoma (PLGA)
D. Wharton’s tumor

Answer 8

B. Mucoepidermoid Carcinoma
It is most commonly found in the parotid gland, followed by the minor salivary glands.
Histologically, it shows a mixture of mucus producing cells and epithelial (epidermoid) cells.
Low-grade tumors have high cyst formation, minimal atypia, and lots of mucous cells.
Intermediate-grade tumors are somewhere in between. There is still cyst formation occurring and all three major types of cells are present, but the intermediate cells predominate. There can be cellular atypia.
High-grade tumors have solid islands of squamous and intermediate cells, which can show lots of pleomorphism and mitotic activity. Mucus-producing cells can be rare.

Question 9

How is low grade mucoepidermoid carcinoma treated?
A. Resection
B. Resection and chemotherapy
C. Resection and radiation therapy
D. Resection with chemotherapy and radiation therapy?

Answer 9

A. Resection

Question 10

What salivary gland tumor is associated with a multifocal presentation?
A. Papillary cystadenoma lymphomatosum (Warthin’s tumor)
B. mucoepidermoid carcinoma
C. pleomorphic adenoma
D. monomorphic adenoma

Answer 10

A. Papillary cystadenoma lymphomatosum (Warthin’s tumor)
These lesions can be bilateral, presenting in both parotid glands

Question 11

Which salivary gland neoplasm does not exhibit neurotropism?
A. Adenoid cystic carcinoma
B. Pleomorphic Low Grade Adenoma
C. Papillary Cystadenoma Lymphomatosum
D. Mucoepidermoid Carcinoma

Answer 11

C. Papillary cystadenoma lymphomatosum (whartin’s tumor)

Salivary gland neoplasms that exhibit neurotropism are: adenoid cystic carcinoma, pleomorphic low-grade adenocarcinoma, mucoepidermoid carcinoma

Question 12

What is the most common histological variant of rhabdomyosarcoma?
A. Embryonal
B. Pleomorphic
C. Botryoid
D. Alveolar

Answer 12

B. Botryoid
Botryoid means “grapelike” and is how rhabdomyosarcoma presents histologically.

Question 13

A melanoma invades through the reticular dermis. What clark level of invasion is this considered?
A. I
B. II
C. III
D. IV
E. V

Answer 13

D. IV
I - confined to dermis
II - Invading papillary dermis
III - Invading papillary-reticular junction
IV - Invading reticular dermis
V - Subcutaneous invasion

Question 14

What is the most common subtype of melanoma?
A. nodula
B. superficial spreading
C. lentigo maligna
D. acral lentignous

Answer 14

B. Superficial Spreading
Superficial spreading, lentigo maligna, and acral lentiginous spread horizontally through the basal layer of the epidermis before growing vertically. In contrast, nodular melanoma has a very short radial growth phase and pretty much just grows vertically.
Lentigo maligna is a slow-growing melanoma with a radial growth phase up to 15 years.
Acral lentiginous melanoma is the most common form of melanoma in blacks and the most common form of oral melanoma.
Melanoma is the third most common skin cancer, but responsible for 75% of skin cancer deaths.

Question 15

What is the most common subtype of basal cell carcinoma?
A. Nodular
B. Sclerosing
C. Pigmented
D. Basosquamous

Answer 15

A. Nodular

Question 16

A SCCa is staged as T2N0M0 base of tongue with a depth of 3mm. What is the indicated treatment?
A. Resection
B. Resection and neck dissection
C. Resection, neck dissection, radiation therapy
D. Resection, neck dissection, radiation therapy, chemotherapy

Answer 16

B. Resection and neck dissection

Neck dissection is indicate in all T2 lesions and higher. It is also indicated in tongue lesions with a depth of invasion of 3-4mm. It is also indicated if there is likelihood of occult metastasis to a regional lymph node > 20% and when the tumor location is the floor of the mouth, tongue, or retromolar trigone. T2 tongue lesions have a metastasis rate of 30% to the regional lymph nodes. They usually spread to levels I-III.

Radiation therapy is not indicated in this case. Indications for radiation therapy include: Extracapsular nodal spread and/or positive margins (requires chemo too). T3 or T4 primary tumor size. N2 or N3 nodal disease. Nodal disease in levels IV or V. Perineural invasion. Vascular embolism.

Question 17

During removal of the submandibular gland, what is the location of the hypoglossal nerve?
A. Medial to the carotid bifurcation
B. Lateral to the hyoglossus
C. Medial to the lingual artery
D. Lateral to the submandibular duct

Answer 17

B. Lateral to the hyoglossus.

The hypoglossal nerve also runs lateral to the genioglossus. It runs lateral to the IJV and carotid arteries. It crosses the submandibular duct several times, so it is both medial and lateral to the duct depending on where you are at along the course of the duct.

Question 18

Which bacteria are implicated in chronic sinusitis?

A. Moraxella caterrhalis, Strep pneumoniae, Staph aureus
B. Strep pneumonia, Haemophilus influenzae, Strep pyogenes
C. Moraxella catarrhalis, Strep pyogenes, Staph aureus
D. Moraxella catarrhalis, Strep pneumoniae, Haemophilus influenzae

Answer 18

D. Moraxella catarrhalis, Strep pneumoniae, Haemophilus influenzae

Question 19

Which bacteria is not implicated in pericoronitis?

A. Peptostreptococcus
B. Fusobacterium
C. Porphyromonas
D. Staphylococcus

Answer 19

D. Staphylococcus

Most common indication for extraction after age 20
* Often associated with operculum (soft tissue flap on distal of crown)
* Acute inflammation with clinical signs and symptoms (pain, swelling, erythema, purulence)
* Associated bacterial types found in gingival crevice of third molars and adjacent teeth
– Obligate and facultative anaerobes lead to purulence (Peptostreptococcus, Fusobacterium, and Porphyromonas)

Question 20

Which antibiotic has the best coverage for actinomyces?

A. Ampicillin
B. Ceftriaxone
C. Keflex
D. Metronidazole

Answer 20

A. Ampicillin

Beta-lactam antibiotics remain the first-line treatment for infections caused by Actinomyces, so ampicillin would be the most appropriate choice.

Question 21

Infection of which space is most likely to lead to trismus?

A. Infraorbital
B. Pterygomandibular
C. Canine
D. Buccal

Answer 21

B. Pterygomandibular

Question 22

What is the mechanism of action of clindamycin?

A. Inhibits DNA gyrase
B. Inhibits 50s ribosomal subunit
C. Inhibits 30s ribosomal subunit
D. Inhibits cell wall synthesis

Answer 22

B. Inhibits 50s ribosomal subunit

Clindamycin works primarily by binding to the 50s ribosomal subunit of bacteria. This agent disrupts protein synthesis by interfering with the transpeptidation reaction, which thereby inhibits early chain elongation.

Beta lactam antibiotics (penicillins, cephalosporins, carbapenems) inhibit cell wall synthesis

Aminoglycosides and tetracyclines (tobramycin, streptomycin, doxycycline) inhibit the 30s subunit.

Fluoroquinolones (ciprofloxacin, levofloxacin) inhibit DNA gyrase and topoisomerase

Question 23

Eikenella corrodens is commonly resistant to which antibiotic?

A. Penicillin
B. Clindamycin
C. Ciprofloxacin
D. Doxycycline

Answer 23

B. Clindamycin

Question 24

A 70-year-old diabetic man who has a history of left sinus symptoms was referred to you for extraction of erupted and loose tooth #15. Your examination revealed marked necrosis of osseous and soft tissue of the left maxilla. You removed several teeth, the necrotic bone and soft tissue, and submitted the specimen to pathology. The pathologist reported necrotic bone and soft tissue with inflammatory infiltrate and the presence of nonseptate irregularly wide fungal hyphae with frequent right- angle branching. Your diagnosis is:
A. Aspergillosis.
B. Candidiasis.
C. Actinomycosis.
D. Mucormycosis.

Answer 24

D. Mucormycosis

Mucormycosis is an aggressive, opportunistic fungal infection caused by fungi of the order Mucorales, which includes genera such as Rhizopus, Mucor, and Apophysomyces. It predominantly affects immunocompromised individuals, including those with poorly controlled diabetes mellitus.[1-3] The characteristic histopathological features of mucormycosis include broad, nonseptate hyphae with right-angle branching, which differentiates it from other fungal infections such as aspergillosis, which typically shows septate hyphae with acute-angle branching

Question 25

What bacteria is commonly implicated in necrotizing fasciitis?

A. Staph aureus
B. E. coli
C. Strep pyogenes
D. Klebsiella pneumoniae

Answer 25

C. Strep pyogenes

Streptococcus pyogenes (group A Streptococcus, GAS) is the most commonly implicated bacterium in necrotizing fasciitis. This pathogen is known for its ability to cause severe invasive infections, including necrotizing fasciitis, which is characterized by rapid tissue destruction and high mortality rates. Other bacteria that can be involved include Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA), and various Gram-negative organisms such as Escherichia coli and Klebsiella pneumoniae. Polymicrobial infections involving both aerobic and anaerobic bacteria are also common.

Question 26

Staining of saliva with Mucicarmine is most likely to identify saliva from which glands?

A. Minor salivary glands
B. Parotid and submandibular glands
C. Submandibular and sublingual glands
D. Submandibular gland only

Answer 26

C. Submandibular and sublingual glands.

Mucicarmine staining is used to identify mucins, which are high molecular weight glycoproteins. The submandibular and sublingual glands are known to produce significant amounts of mucins, specifically MG1 and MG2.

Question 27

What is the preferred treatment for a calcifying epithelial odontogenic tumor?

A. Enucleation and curettage
B. Resection with 0.5 cm margins
C. Resection with 1.0 cm margins
D. Enucleation and treatment with 5-fluorouracil

Answer 27

C. Resection with 1.0 cm margins

The preferred treatment for a calcifying epithelial odontogenic tumor (CEOT) is resection with 1.0 cm margins. This approach is recommended due to the potential locally aggressive behavior of the tumor, which can lead to recurrence if not adequately excised. Enucleation and curettage are associated with higher recurrence rates and are generally considered less effective.

Question 28

Which of the following is most likely to cause airway obstruction?

A. Vallecular cyst
B. Ranula
C. Submandibular sialadenitis
D. Parotid sialadenitis

Answer 28

A. Vallecular cyst

A vallecular cyst is a fluid-filled sac located in the vallecula, the depression between the base of the tongue and the epiglottis and growth can lead to airway obstruction.

Question 29

Which of the following is the standard treatment for mandibular osteosarcoma?
A. Chemotherapy and radiation only
B. Surgical resection with a wide (2-3 cm) margin and consideration for preoperative and postoperative chemotherapy
C. Surgical resection with a wide (2-3 cm) margin and planned post-operative radiation
therapy
D. Surgical resection with a wide (2-3 cm) margin following neo-adjuvant chemotherapy and radiation therapy

Answer 29

B. Surgical resection with a wide (2-3 cm) margin and consideration for preoperative and postoperative chemotherapy

Surgical resection with clear margins is the cornerstone of treatment for mandibular osteosarcoma. The National Comprehensive Cancer Network (NCCN) guidelines recommend wide excision as the primary treatment for high-grade osteosarcomas, with preoperative chemotherapy preferred to improve surgical outcomes and increase the probability of achieving clear margins.
Additionally, neoadjuvant chemotherapy improves disease-free and metastatic-free survival and increases the rate of clear surgical margins from 50% to 68%. Postoperative chemotherapy is also considered to further reduce the risk of recurrence.

Question 30

In soft tissue flaps, what contributes most to survival in the first 2-3 days after surgery?

A. Capillary ingrowth
B. Plasmatic imbibition (dermal side)
C. Circulation by anastamosis
D. Inosculation

Answer 30

B. Plasmatic imbibition (dermal side)

In the first 2-3 days after surgery, the survival of soft tissue flaps is primarily dependent on plasmatic imbibition (dermal side). This process involves the absorption of nutrients and oxygen from the wound bed exudate into the flap tissue, which is critical before revascularization occurs.

Question 31

Which factor is most prognostic in treating a melanoma?

A. size
B. shape
C. color
D. depth of invasion

Answer 31

D. depth of invasion

Multiple studies have reinforced the importance of depth of invasion as the most prognostic factor in melanoma. Breslow thickness, which measures the depth of the tumor from the top of the granular layer of the epidermis to the deepest point of invasion, is consistently highlighted as the most significant predictor of survival outcomes in melanoma patients.

Question 32

What is the arterial supply to the trapezius flap?

A. dorsal scapular artery
B. superior scapular artery
C. supraclavicular artery
D. transverse cervical artery

Answer 32

A. dorsal scapular artery

Two types
– Superior trapezius flap
– Lower island trapezius flap
* Common indications: Lateral neck and skull cutaneous defects
* Arterial supply: Dorsal scapular artery

Question 33

What is the most common histological variant of rhabdomyosarcoma?

A. Embryonal
B. Alveolar
C. Spindle Cell/Sclerosing
D. Pleomorphic

Answer 33

A. Embryonal

Embryonal:
Considered the most common type, with small, round cells often arranged in clusters or sheets, and is usually seen in younger children.

Alveolar:
Characterized by a distinctive “alveolar” pattern with cells arranged in a honeycomb-like structure, often associated with specific genetic abnormalities and a higher risk of recurrence.

Spindle cell/sclerosing:
Composed of elongated spindle-shaped cells with a dense fibrous stroma, sometimes considered a variant of embryonal rhabdomyosarcoma.

Pleomorphic:
The most aggressive variant with large, pleomorphic cells, prominent nucleoli, and frequent mitotic figures.

Question 34

What is the most common variant of osteosarcoma?

A. Juxtacortical
B. Intramedullary
C. Extraskeletal
D. Parosteal

Answer 34

B. Intramedullary

The most common type of osteosarcoma is intramedullary osteosarcoma, which accounts for about 80% of all osteosarcoma cases

Juxtacortical osteosarcoma: The second most common type, accounting for 10–15% of cases. These tumors develop on the outer surface of bones or the periosteum.
Extraskeletal osteosarcoma: A rare type that accounts for less than 5% of cases. These tumors develop in soft tissues and are not attached to bone.
Parosteal osteosarcoma: A type of osteosarcoma that is usually low-grade

Question 35

Which of the following markers is most typical of a central giant cell granuloma?

A. CD34
B. CD68
C. CD44
D. CD1a

Answer 35

A. CD34

CD68 is most often expressed in a peripheral giant cell granuloma.

CD44 is often a marker of aggressiveness in an ameloblastoma.

CD1a and S100 are markers for langerhans cell histiocytosis