Xeroradiographic Studies in 150 Patients with Solitary Scintigraphically Nonfunctioning Nodules of the Thyroid Gland 1

Diagnostic Radiology

Heribert G. Reichelt, M.D., Alfons Brase, M.D., Heinz Hundeshagen, M.D., and Hans S. Stender, M.D. Xerorad iographic studies were performed in 150 patients with a solitary scintigraphically nonfunctioning nodule of the thyroid gland. This procedure was demonstrated to be superior to conventional radiographic techniques in imaging the trachea, in the visualization of the cervical subcutaneous and visceral compartments and in the identification of cystic walls . It is also a sensitive methOd for the detection of calcifications. Psammoma bodies are typical for malignant changes in nodes whereas other types of microcalcifications are nonspecific. Coarse, amorphous calcifications are typical for benign adenomas with regressive changes; shell-like calcifications are seen in longstanding cysts. TERMS: Thyroid, cysts. Thyroid, neoplasms. (Thyroid gland, xeroradiography, 2[73] .1299) • Xeroradiography

INDEX

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portant for imaging small lesions and microcalcifications, especially in the lower cervical regions (1, 2, 9, 12). In this paper, we present our experience with xerora-

have been made in xeroradiography, with substantial gains in edge enhancement and wide image latitude (8,9, 12). This is particularly im-

C

ONSIDERABLE ADVANCES

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Fig. 1. Coarse dense calcifications of different sizes are seen. Histology: struma nodosa colloides with regressive changes and coarse-grained calc ifications. Fig. 2. Fine amorphous calcifications widely scattered within a large solid " cool" nodule. Histology: benign adenoma with widespread regressive changes and calcifications. Fig. 3. Small calcified cyst within a " cool" area of a struma nodosa. Histology: struma colloides with regress ive changes .

1 From Department fOr Radiologie, Abteilung fOr Nuklearmedizin und spezielle Biophysik (H.G.R., H.H., Professor) und Abteilung fOr klinische Radiologie (A.B., H.S.S., Professor), Medizinische Hochschule Hannover, West Germany . Accepted for publication in July 1977. shan

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December 1977

MATERIALS AND METHODS

Xeroradiographic studies were done in 150 patients with a solitary palpable nodule in the thyroid gland which was scintigraphically "cold" (no uptake) or "cool" (uptake less than the surrounding thyroid tissue) . The scans were taken 24 hours after oral ingestion of iodine-131. For the xeroradiographic studies, the Rank Xerox System 125 was used. Anteroposterior (AP), lateral and oblique views were taken with the patient in the prone or sitting position (50 kV; 160-200 mAs; focus 0.6 mm). All patients had additional conventional radiographs of the cervi co-thoracic region in AP and lateral views for examination of the trachea and the upper mediastinum. Needle biopsies (15 gauge, 20-ml syringe) were done in all patients. In 40 cases, scintigraphically nonfunctioning nodules were cystic. Fluid was aspirated and replaced by the same amount of air (3, 10, 14). Neither biopsy nor insufflation of cysts was done under local anesthesia. There were no complications. In all cases, final diagnosis was established by surgery and histologic studies. RESULTS

Xeroradiographic studies of the thyroid gland and its adjacent anatomical structures always give an excellent impression of the trachea (Figs. 1-6). Displacement or narrowing by struma and/or nodes as well as irregularities of the tracheal wall in tracheomalacia or by invasion and penetration of thyroid carcinoma can be detected without difficulty. The technique usually allows sufficient delineation of the suprasternal visceral compartment of the neck in its fascial envelope against the subcutaneous tissue (Figs. 4 and 6). Xeroradiography is particularly suited for investigation of cysts of the thyroid gland in combination with thyroid pneumocystography. The walls of the cysts were well delineated in all views. In 40 cases, the walls of all cysts were entirely smooth; none of the cysts was malignant.

Fig. 4. Medium-sized struma nodosa . A benign cyst is seen within regressive changes of the thyroid gland. There are shell-like calcifications in the wall of the cyst (arrows) and amorphous calcifications in the vicin ity of the cyst. Note the excellent demarcation of subcutaneous tissue against the anterior border of the substernal and the visceral compartment of the neck.

diography in the diagnosis and differentiation of solitary nonfunctioning (scintigraphically "cold") nodules of the thyroid gland.

TABLE I: CALCIFICATION PATTERNS IN BENIGN AND MALIGNANT THYROID NODULES

Histology

Number of Patients

Amorphous

ShellLike

Microcalcifications Multilocular (m) Clusters (c)

Benign Solid adenoma and adenoma with regressive changes Follicular adenoma Cysts-colloidal hemorrhagic Focal thyroiditis Hashimoto thyroidits Malignant Papillary Follicular carcinoma Anaplastic Metastas is of bronchogenic carcinoma Total

73 18 27 13 2 2

45 3 19 4

7 5 2 _1 , 150

1 1 2

2 9 2

total

Psammoma Bodies

17 (m) 5 (c) 4(m+c) 26 1 (c) 7(m) 3(m) 1(m)

2 (c) 1 (c)

No Calcifications

24 15 12 8 1 2

2

2 3 1

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Diagnostic Radiology

Fig. 5. A. Thyroid pneumocystography. The anterior view shows a large air-filled cyst with smooth walls. The cyst displaces and narrows the trachea (arrows). B. Benign cyst. Note smooth walls above the fluid level. Calcifications are seen on the thyroid and tracheal cart ilages.

A wide variety of calcification was seen in the scintigraphically nonfunctioning nodules of 82 patients (TABLE I). The following patterns can be differentiated: (a) Coarse, amorphous calcifications of irregular, scattered grouping. They have sharp contours and exhibit great variability in size and shape (Figs. 1, 2 and 4). (b) Shell-like calcifications outlining the walls of thyroid cysts (Figs. 2, 3 and 4). (c) Microcalcifications (400-1,000 J.I.). They can be found as a single calcified focus or clumped together in clusters. Usually they are of low density and present a blurred appearance. Histologically verified psammoma bodies showed irregular, spiculated microcalcifications (Fig. 6). (d) Combinations of the three types mentioned above (Figs. 1, 2, 4 and 6) but microcalcifications in psammoma bodies were never seen with other kinds of calcifications within the same area. DISCUSSION

A "cold" or "cool" nodule in the thyroid gland always requires further investigation. In several series, the incidence of carcinoma in solitary cold nodules varied from 5.5 to 54% (4); the average lies between 10-25% , a wide

range which may depend upon regional conditions. In the present series, the actual incidence of thyroid carcinoma was 9.3 %. Approximately 91 % of the nodes represented benign conditions such as benign adenomas or adenomas with regressive changes, colloid-filled and hemorrhagic cysts and focal thyroiditis. (In one case, however, a cold node which caused a deformation of one thyroid lobe proved to be the first clinical sign of bronchogenic carcinoma .) Xeroradiography is superior to conventional radiographic methods because it permits critical evaluation of the trachea. Displacement and narrowing of the trachea caused by cysts and nodes can be seen extremely well (11). The diagnosis of one advanced papillary and one anaplastic thyroid carcinoma was established on findings along the tracheal wall. Cont inuous neoplastic penetration of the tracheal wall was confirmed by bronchoscopy and biopsy. The border between the subcutaneous tissue and the outer fascial layer of the cervical visceral compartment is usually recognizable. Indistinct or absent demarcations are often the result of difficulties in positioning patients for optimal views (e.g., age, short neck, etc.) . Irregularity and retraction of the outer fascial layer together with the thyroid capsule was seen only once in combination with psam-

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of malignancy if microcalcifications typical for psammoma body formation are seen. Other authors argue that this is ample evidence of malignancy (6, 13). We recommend immediate histological examination in such cases. Shell-like calcifications of large extent within longstanding nodes seem to be typical for benign colloidal cysts. Other patterns of calcification did not enable us to distinguish benign from malignant lesions. Although xeroradiography cannot completely differentiate all solitary nonfunctioning thyroid nodules, its image quality is superior to that of conventional radiography and it should be the technique of choice in further therapeutic follow-up. ACKNOWLEDGMENTS: We wish to thank Miss A. Dittmann and Miss G. Langenberg for their technical help.

H. Reichelt, M.D. Department Radiologie Abteilung fOr Nuklearmedizin und spezielle Biophysik Medizinische Hochschule Hannover 3000 Hannover West Germany

~I Fig. 6. Typical microcalcifications in a psammoma body in a case of papillary carcinoma. Note the irregularity of the anterior border of the thyroid gland due to capsule retraction by the carcinoma (arrow) .

moma body formation in a patient with papillary carcinoma. Air-filled cysts are particularly suited for xeroradiographic examination. (We avoided injection of contrast material because of the risk of iodine contamination of the body.) Xeroradiography seems to be justified because of the excellent delineation of the cystic walls. Completely smooth walls always proved benignity in colloid-filled as well as hemorrhagic cysts. Within our group no patient showed cystic changes in malignant nodes . Xeroradiography does not permit evaluation of internal structures of the thyroid gland. We saw a surprising variety of calcifications. Extrathyroidal calcifications in neighboring structures of the thyroid gland (e.g., trachea , thyroid cartilage, carotid artery) usually can be ruled out by different projections. Calcifications in the thyroid gland have already been investigated with conventional soft-tissue roentgenography in conjunction with histologic studies (2, 5, 7, 13). Our results show that there is only a strong suspicion

REFERENCES 1. Adler D, Evers R, Frastel A: Die Xeroradiographie des Halses und der Spelcheldrusen. Laryngol Rhinol 0101 54:623-629, Aug 1975 2. Brase A, Lang H, Ziegler H, et al: Der Wert der Xeroradiographie in der praoperatlven Diagnostik maligner Schilddriisenerkrankungen. Roentgenblaetter 29:221 -229, May 1976 3. Catalano D, Pierangeli LF: Die Differenzierung kalter Knoten der Schilddriise 'durch Thyreoidea-Zystographie. Fortschr Geb Roentgenstr Nuklearmed 121:527-528, Oct 1974 4. Freyschmidt P: Sch ilddriisenerkrankungen. Stuttgart, Georg Thieme Verlag, 1968 5. Holtz S, Powers WE: Calc ification in papillary carcinoma of the thyroid. Am J RoengenoI80:997-1000, Dec 1958 6. Klinck GH, Winship T: Psammoma bodies and thyroid cancer. Cancer 12:656-662, Jul-Aug 1959 7. Margolin FR, Winfield J, Steinbach HL: Patterns of thyroid calcification: roentgenolog ic-histologic study of excised specimens. lnvest RadioI2:208-212, May-Jun 1967 8. Puppe D: Xeroradiographie-Grundlagen und Anwendungsmoglichkeiten. Ergebn med radiol Vol. III. Stuttgart, George Thieme Verlag , 1971 9. Reinhard B, Evers R, Fischedick 0: Skelett- und Weichteildarstellung in der Xeroradiographie. Fortschr Geb Roentgenstr Nuklearmed 120:209-215, Feb 1974 10. Rozenshtrauck LS, Ponomarev LE: Pneumothyroidography in diseases of thyroid gland. Fed Proc (Transl. Suppl) 23:392-396, MarApr 1964 11. Schein CJ, Lentino W, Jacobson HG: Relation of thyroid enlargement to tracheal configuration: anatomico-roentgenologic correlation . New Engl J Med 255:1072-1075,6 Dec 1956 12. Scherte l L, Kraska H, Hiithwohl B: Zur Xeroradiographie des Thorax. Fortschr Geb Roentgenstr Nukleamed 122:417-422, May 1975 13. Segal RL, Zuckermann H, Friedmann EW: Soft tissue roentgenography : its use in diagnos is of thyroid carcinoma. JAMA 173: 1890-1894,27 Aug 1960 14. Thommesen P: Thyreoideazystographie. Fortschr Geb Roentgenstr Nuklearmed 114:616-619, May 1971

Xeroradiographic studies in 150 patients with solitary scintigraphically nonfunctioning nodules of the thyroid gland.

Xeroradiographic Studies in 150 Patients with Solitary Scintigraphically Nonfunctioning Nodules of the Thyroid Gland 1 Diagnostic Radiology Heribert...
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