Radiology/Pathology Correlation

Unknown 2

The patient is a 50-year-old woman with a three-week history of chest pain, weight loss, and cough. Her past history is remarkable for prior crack use, and a smoking history of 2-3 cigarettes per day for 20 years.

Radiology

Chest Radiograph

Figure 1

Describe the lesion.

Is lymphadenopathy present? Answers

 

Axial Chest CT

Figure 2

Describe the CT. Is an air-fluid level present?

Give a diffential diagnosis. Answers


Pathology

 

Figure 3

Gross Appearance of Cavity

This image shows a similar lesion from a different patient.

What does the white tissue at the top of the cavity probably represent?

In the surrounding lung, note the prominence of the linear interlobular septa. What vessels are present in these septa?

What is the significance of the color of the lung parenchyma?

Answers

 

pearlnewpearl

Figure 4

Describe the histologic features of the tumor. Answer

 

 

pearlnewpearl

Figure 4

Description of Tumor

Nests of tumor, surrounded by a fibrous stroma, have small cells at the edge and larger, more differentiated cells with more cytoplasm centrally. Note the irregular shapes and hyperchromaticity of some of the tumor nuclei.

These nests resemble skin with basal cells at the edge and differentiating cells centrally.

 

Find 2 examples of keratinization of tumor cells. Click on the structure in the image to get verification.

 

 

bridge1bridge2bridge3

Figure 5

This image shows another characteristic of this tumor: desmosomes or bridges (the ladder-like junctions between cells).

Find examples of intercellular bridges (desmosomes).

 

 

What is the histologic diagnosis? Answer

Comments on the Radiographic Features

The solitary pulmonary parenchymal cavity is not an uncommon problem. The differential diagnosis can frequently be narrowed by using clinical criteria. For example, an irregular cavity in a patient with poor dentition and recurrent aspiration suggests pyogenic lung abscess as the likely etiology. Certain chest radiographic features may also be used to direct further evaluation of a solitary cavity, particularly the maximum thickness of the cavity wall. If the cavity wall is 1 mm or less at its thickest portion, the cavity is overwhelmingly likely to be benign. In a study addressing this issue [1], if the thickest portion of the cavity wall was 4 mm or less, 92% of such lesions were benign. On the other hand, cavities with maximum wall thicknesses exceeding 15 mm were usually (95%) malignant. In this same study [1], if the maximum thickness of the cavity wall was between 5 and 15 mm, 51% of lesions were benign and 49% malignant. CT scanning may provide further demonstration of the morphology of a cavity, especially the character of the inner lining of the cavity. An irregular, lobulated inner lining suggests malignancy, although such features may be seen with infections.

Comments on the Histologic Features

Pure squamous cancers vs combined types: The histologic examples depict a well-differentiated squamous carcinoma. In poorly-differentiated tumors, bridges and pearls are less apparent, and careful search for them is necessary. Also, some tumors have features of combined adenocarcinoma and/or small cell carcinoma. Thus, a stain for mucin (PAS after diastase digestion) for adenocarcinoma, and a stain for neuroendocrine cells (chromogranin) for small cell carcinoma in addition to the morphology by H&E stain are required for the correct diagnosis. An example of a combined small cell, squamous, and adenocarcinoma may be seen here and here. Whereas a combined adenosquamous cancer is treated in the same way as a squamous cancer, a combined squamous/small cell cancer is treated as a small cell carcinoma.

Primary vs metastasis: Morphologic criteria for distinguishing a primary lung cancer from a metastasis have been described [3]. Molecular methods using analysis of p53 mutations have been examined recently, but are not yet used clinically [4].

Asbestos as an etiology: Although the cause of lung cancer is mainly cigarette smoking, asbestos is another contributing factor. Search of histologic sections of lung tissue (not tumor tissue) for asbestos bodies is one way to confirm an exposure to asbestos. Finding more than 0.5 asbestos bodies/square cm of lung tissue indicates a heavy exposure. However, these bodies are diagnostic of asbestos only when there is a history of asbestos exposure: other fibrous minerals may have a similar appearance. The generic term is ferruginous body.

Aspergilloma in the differential diagnosis: Two recent case reports note the similarity of the radiographic findings in aspergilloma and cavitary lung cancer. abstract, abstract

Black pigment: Smoking crack cocaine produces focal or diffuse (as in this case) intra-alveolar black deposits, which do not stain for iron. Pigment is free or in macrophages. Interstitial black pigment may have another source.

Final Diagnosis: Primary squamous carcinoma of the lung with chest wall invasion.

References:

1. Woodring JH, Fried Am, Chuang VP. Solitary cavities of the lung: diagnostic implications of cavity wall thickness. AJR 1980; 135:1269-1271. abstract

2. Woodring JH and Fried AM. Significance of wall thickness in solitary cavities of the lung: a follow up study. AJR 1983; 140:473-474.

3. Martini N, Melamed M. Multiple primary lung cancers. J Thorac Cardiovasc Surg 1975; 70:606-611.

4. van Rens M, Eijken E, Elbers J, Lammers J, Tilanus M, Slootweg P. p53 Mutation analysis for definite diagnosis of multiple primary lung carcinoma. Cancer 2002; 94:188-196. abstract

Last revised 5/13/02

TOP----------Rad/Path Home Page

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The frontal chest radiograph shows a cavity with an irregularly thickened wall in the left lung apex. The superior wall of the cavity is thicker than other portions of it. No evidence of lymphadenopathy is present.

Return

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Axial CT of the chest reveals a left upper lobe cavity in contact with the chest wall posteriorly. The inner margin of the cavity is irregular, and the wall thickness is variable, measuring approximately 1.8 cm at its thickest portion. The erosion of the rib indicates involvement of the chest wall. No air-fluid level is present.

Differential Diagnosis: The differential diagnosis of a solitary lung cavity includes primary neoplasm (especially squamous carcinoma); solitary metastasis (also commonly squamous carcinoma); bacterial lung abscess (including mycobacterial); fungal infections (especially aspergillus); parasitic infections (particularly hydatid disease); pulmonary infarction; several non-infectious inflammatory lesions, including Wegener's granulomatosis, rheumatoid arthritis, and amyloidosis; and bronchogenic cyst.

Return

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3

Gross Appearance of Cavity

This image shows a similar lesion from a different patient.

What does the white tissue at the top of the cavity probably represent?

In the surrounding lung, note the prominence of the linear interlobular septa. What vessels are present in these septa?

What is the significance of the color of the lung parenchyma?

Answers

The white tissue represents neoplasm. Compare it with the necrotic lung tissue in Unknown 1 (use the "back" button in the menu bar to return).

Pulmonary veins and lymphatics run in the interlobular septa.

The very dark lung parenchyma is suggestive of diffuse deposition of black pigment, as is found in smokers of crack cocaine.

Return

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Desmosomes (bridges)

Return

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fully keratinized cells that have formed a rounded "pearl". Only traces of nuclei remain. The white space represents a shrinkage artifact incurred in processing.

Return

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Group of partially keratinized cells beginning to round up to form a "pearl". Nuclei are still present.

Return

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Well-differentiated squamous carcinoma. Diagnosis requires a typical growth pattern and the presence of desmosomes (bridges) or keratinization (pearl formation).

Return