Aunt Minnies and Classics

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AUNT MINNIES/CLASSICS

An Aunt Minnie case is like your familiar

Aunt. You just look at her and you recognize her. That’s who it is. It doesn’t take a lot of analysis if you know her.

The following is an Aunt Minnie

In the preceding case, the most obvious abnormality is a large cardiac silhouette

Although it is often difficult to assess specific cardiac chamber size on CXR, in this case the heart is enlarged inferiorly and laterally to the left suggesting that this heart has left ventricular enlargement, perhaps due to chronic hypertension

In this case the patient does have longstanding hypertension, due to an etiology which can be diagnosed on CXR

The Aunt Minnie finding here is rib notching, indicating coarctation of the aorta (see following magnification view of ribs)

Although coarctation can present even at birth if severe enough, milder cases may even present in adulthood, as in this 67-year-old patient

The coarctation typically causes a stenosis of the thoracic aorta just after the origin of the left subclavian artery, resulting in hypertension in the upper body, but not lower (this is like renovascular hypertension, but with the stenosis even farther upstream)

The rib notching is caused by collateral flow around the coarctation

(subclavians to internal mammaries to anterior intercostals to posterior intercostals to descending aorta)

The notching is on the bottom of ribs only since that’s where the vessels travel

Rib notching is not usually seen under age 7, because it takes time for the collaterals to enlarge, become tortuous, and eroding the ribs

Another classic case on the following 2view CXR

Finding most apparent on the lateral

The preceding CXR shows an anterior mediastinal mass, due to a thymoma in this case

There is a classic differential diagnosis for an anterior mediastinal mass that can be remembered using the 4 T’s

– Thymoma

– Thyroid (intrathoracic goiter, usually in an elderly female)

– Teratoma (to make it a T, but other mediastinal germ cell tumors like seminoma also)

– T-cell lymphoma (to make it a T, but any Hodgkin or non-Hodgkin lymphoma

Following is a CT on the preceding thymoma case

Note how the tumor projects into each hemithoax, causing the subtle extra edge shadows on the PA CXR

The mass contains calcifications, common in thymomas, mediastinal goiter, and teratoma, but uncommon in lymphoma unless previously treated

The following is another Aunt Minnie

A key finding is the two calcifications (that look a lot like teeth) just to the right of midline on this pelvic X-ray

These are teeth in an ovarian teratoma

Note the large subtle oval low-density area around the teeth.

This is the fatty/oily component of the teratoma

Teratomas contains representative tissue from all 3 germ layers (endoderm, mesoderm, and ectoderm). Since ovarian teratomas often contain mostly ectodermal elements they are also called ovarian dermoids

Ovarian teratomas/dermoids typically contain fatty/oily secretions produced by sebaceous glands (ectodermal), more easily seen on CT and MR than on X-ray. A hair ball is also common (also ectodermal). Teeth (partially ectodermal) are a less common finding, but a classic

Here’s another classic on the following 3 CXR images

Note the fine fuzzy nodular pattern, most apparent on the magnified view

Although there is a differential for this snowstorm of small nodules, the classic diagnosis is miliary TB, which this patient had

Miliary refers to millet, a grain seed that measures a couple mm in size

Other diagnoses in the differential include overwhelming fungal and viral infections, metastatic disease, and silicosis

This represents hematogenous spread of TB and usually takes about 6 weeks to become visible on CXR

The following CXR is another Aunt Minnie

Note the RUL lung opacity, but also note the fairly well-circumscribed irregular lucency within the infiltrate

The lucency should suggest a cavity

An upper lobe infiltrate (TB likes the higher oxygen environment there) with a central cavity should suggest TB, the diagnosis in this case

This is an important diagnosis because the presence of a cavity makes it likely that there is communication with the bronchial tree and that the patient if coughing out live TB

The infiltrate surrounding the cavity is probably due to endobronchial spread of TB

The following 2-view CXR is another Aunt Minnie

Note the large lobular masses centered on both hila.

The differential for hilar enlargement includes dilated pulmonary arteries and adenopathy. In this case the location and lack of branching indicate adenopathy

This is symmetrical bilateral hilar adenopathy which is classic for sarcoid. Note that there is also right paratracheal adenopathy (the classic 1-2-3 sign).

Lung CA (typically oat cell) and lymphoma are common causes of adenopathy in the chest, but these would not usually give symmetrical hilar adenopathy

The following AP portable CXR is shown to emphasize the importance of evaluating manmade objects on a CXR

Often the position of tubes, wires, and other man-made objects is at least as important to check as the pneumonia or other pathology on the CXR

Present on this CXR are cardiac monitor wires, left subclavian Swan-Ganz catheter, and endotracheal tube, all in good position

There is another tube, better shown on the following magnification view

The metal weighted tip of the tube indicates that it is a

Dobhoff feeding tube (the CXR was taken to confirm appropriate position before starting tube feeds)

The Dobhoff turns laterally in mid-chest following the left mainstem bronchus, indicating that it is in the lung and not the esophagus (it would stay closer to midline if in esophagus)

The S-shaped distal portion of the tube and its weighted tip have perforated through the visceral pleural surface of the LLL and are in the pleural space

(the posterior costophrenic angle)

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