THORACIC Section 5: Lung Cancer: Mimics and Other Cancers Flashcards
Diagnosis?
Pulmonary Hamartoma
Described to have macroscopic fat and “popcorn calcifications”
Pulmonary Hamartoma
The most common benign lung mass
Pulmonary Hamartoma
The most common lung tumor in patients with AIDS
Kaposi Sarcoma
The favored location of Kaposi Sarcoma
tracheobronchial mucosa and perihilar lung
Most common hepatic neoplasm in AIDS
Kaposi Sarcoma
Flame Shaped opacities
Kaposi Sarcoma
Diagnosis?
Describe the lesions
“Flame-shaped” Hilar opacities
3 categories of metastatic lung disease
- Direct Invasion
- Hematogenous Mets
- Lymphatic Carcinomatosis
What type of metastatic disease do these common situations belong?
Esophageal CA
Lymphoma
Malignant Germ Cell Tumor
Direct Invasion
This is seen with cancer of the
mediastinum, pleura, or chest wall. More rarely you are going to have mets to the pleura than
invading the lung. Even more rarely you can have malignant
mesothelioma, which can invade the lung
Direct Invasion
The most common manifestation of hematogeneous mets to the lung
Pulmonary nodule
Describe the pulmonary nodule as a common manifestation of the hematogenous mets to the lung
Multiple in a random distribution favoring the lower lobes
“Cannonball Mets” are classically from what type of CA?
renal cell or choriocarcinoma (testicle)
Main culprits of hematogenous mets
Breast, kidney, thyroid, colon and head and neck squamous cells - classically cavitate
A prominent pulmonary vessel heading into a nodule
Feeding Vessel Sign
What are the things to consider if you see a prominent vessel heading into a nodule?
- Hematogenous mets or
- Septic emboli
The most common cause of unilateral Lymphangitic Carcinomatosis?
Bronchogenic Carcinoma invading the lymphatics
The most common extrathoracic culprits of Lymphangitic Carcinomatosis
Breast
Stomach
Pancrease
Prostate
CT finding of Lymphangitic Carcinomatosis (LC)
The finding is nodular thickening of the interlobular septa and subpleural interstitium. Unlike interstitial fibrosis, this thickening classically does NOT distort the pulmonary lobule
What are the 4 flavors of Pulmonary Lymphoma?
Primary
Secondary
AIDS related
Post-transplant lymphoproliferative Disorder (PTLD)
What are the radiographic patterns of Lymphoma?
Lymphangitic spread (uncommon)
parahilar airspace opacities
mediastinal lymphadenopathy
This is a rare type of Pulmonary Lymphoma, and usually non-Hodgkin in subtype. You define it as the lack of extrathoracic involvement for 3 months. Almost always (80%) we are talking about a low grade MALToma.
Primary pulmonary Lymphoma
Here we are talking about pulmonary involvement of a systemic lymphoma. This is much much much more common than primary lung lymphoma.
Secondary Pulmonary Lymphoma
80-90% of lymphoma cases
Secondary NHL
Type of Secondary Lymphoma
45% have intrathoracic disease at presentation
Secondary Non-Hodgkin Lymphoma
Type of Secondary Lymphoma
25% have pulmonary
parenchymal disease
Secondary NHL
Type of Secondary Lymphoma
Pulmonary involvement
frequently occurs in the
absence of mediastinal
disease
Type of Secondary Lymphoma
Pulmonary involvement
frequently occurs in the
absence of mediastinal
disease
Secondary NHL
Type of Secondary Lymphoma
10-20% of lymphoma
cases
Secondary HL
Type of Secondary Lymphoma
85% have intrathoracic
disease at presentation
Secondary HL
Type of Secondary Lymphoma
40% have pulmonary parenchymal disease
Secondary HL
Type of Secondary Lymphoma
Lung involvement almost always associated with intrathoracic lymph node enlargement
Secondary HL
Post-Transplant Lymphoprolipherative Lung Disease usually occurs when?
Within a year (late presentations >1 year have a more aggressive course)
This is a B-Cell lymphoma,
with a relationship with EB Virus.
Post Transplant Lymphoprolipherative Disorders (PTLD)
Type of Lymphoma
The typical look
is well-defined pulmonary nodules / mass, patchy airspace consolidation, halo sign, and interlobular
septal thickening.
PTLD
This is the second most common lung tumor in
AIDS patients (Kaposi’s is first).
AIDS related pulmonary lymphoma (ARL)
Aids Related Lymphoma (ARL) is seen in patients with a what CD4 levels?
CD4 < 100
The most common radiologic presentation of ARL
multiple peripheral nodules ranging from 1 cm-5 cm
What do you consider if you see and AIDS patient with lung nodules, pleural effusion and lymphadenopathy?
Lymphoma
A potassium analog. Things with a functional Na/K/ATP pump tend to be alive.
Hence anything this is “alive” will be thallium positive.
Thallium
is an Iron analog. Iron is an inflammatory marker (acute phase reactant) hence things that are “smoldering” tend to be gallium negative, and things that are inflamed - infection, active sarcoid, most cancers - tend to be Gallium hot.
Gallium
Kaposi Sarcoma vs Lymphoma
Thallum Positve
Gallium Negative
Kaposi Sarcoma
Kaposi Sarcoma vs Lymphoma
Thallum Positive
Gallium Positive
Lymphoma
