مقالات پذیرفته شده در هشتمین کنگره بین المللی زیست پزشکی
Features of an adrenal cortical carcinoma on CT scan: A case report
Features of an adrenal cortical carcinoma on CT scan: A case report
Ramin Ebrahimi,1Mohammad-Ali Mohammadi-Vajari,2Milad Benam,3Erfan Mohammadi-Vajari,4,*
1. Firouzgar clinical research center(FCRDC), Iran university of medical sciences (IUMS), Tehran, Iran 2. Firouzgar clinical research center(FCRDC), Iran university of medical sciences (IUMS), Tehran, Iran 3. Firouzgar clinical research center(FCRDC), Iran university of medical sciences (IUMS), Tehran, Iran 4. Guilan University of Medical Sciences
Introduction: Adrenal lesions can have a wide range of differential diagnosis from benign masses to malignant tumors. Despite the small size of the adrenal glands, they are involved with numerous neoplasms, such as adenoma, myelolipoma, cortical carcinoma, pheochromocytoma, neuroblastoma and many metastases.
Along with laboratory tests, radiology plays an essential role in the differentiation and diagnosis of adrenal lesions. Adrenal adenomas are the most common lesions detected on a CT scan. Incidentalomas are lesions that are accidentally found in adrenal imaging, to which the approach is detailed in the American College of Radiology (ACR) guideline, its latest version reviewed in 2017.
The case presented in this article is a young woman with a mass on the left side of the abdomen originating from the left adrenal gland. The prominent goal of this study is to highlight the different features and the noteworthy appearance of this tumor in CT scan images as well as the importance of laboratory examinations and clinical data in making the final diagnosis.
Methods: The patient was a 27-year-old woman with a firm enlargement in the left side of the abdomen for 2 months prior to admission. The mass had expanded to the entire left side of the body, and the patient had a past medical history of hirsutism since six years ago. The initial abdominal and pelvic ultrasound revealed a huge heterogeneous mass (approximately 155 × 134 mm) in Left Upper Quadrant (LUQ) extending to the entire abdominal cavity. For further evaluation, abdominal and pelvic CT scan was performed.
Results: Spiral abdominopelvic CT scan with and without contrast showed a large left retroperitoneal mass measuring 115 × 150 × 160 mm and originating from the left adrenal gland with a heterogeneous density containing necrotic areas and coarse calcification. Significant heterogeneous enhancement was detected after injecting the contrast agent. The compressive effect of the mass on the left gonadal vein (ovarian vein) led to its varicose dilation, as well as significant congestion of the pelvic veins. Numerous collateral vessels developed around the mass suggested the hyper vascular nature of a malignant tumor. The compressive effect of this mass was seen on the body and tail of the pancreas, as well as the transverse colon and the left kidney. Significant contrast-enhanced lymphadenopathies were also seen in the paraaortic space with a maximum short-axis diameter (SAD) of 8 mm. In triphasic CT scan, several diffuse masses were seen in both lobes of the liver with the largest dimensions of 25 × 28 mm in segment 5 of the liver, which were isodense with the liver on pre-contrast phase. These masses showed hyperenhancement in the arterial phase and became relatively hypodense compared to surrounding liver parenchyma in the delayed phase (also called a washout appearance). The above findings were suggestive of hyper vascular liver metastases. After additional examinations and analysis of the laboratory data, The patient underwent an Octreotide scan which revealed normal homogenous tracer activity in liver, spleen and urinary system, without any significant abnormality or avid lesion. Finally, the patient underwent complete left adrenalectomy and left nephrorrhaphy. After a laparotomy incision on the upper part of the abdominal wall, the descending and transverse colon were medialized and the adrenal gland and part of the mesocolon were released. During the surgery, very large collateral vessels were observed and a thrombosed left adrenal vein was detected, which was ligated and cut further into the surgery. Adhesions to the pancreas were slowly released as well. During the adrenal release, the upper pole of the left kidney lacerated and nephrorrhaphy was
performed separately, however, the urinary system was preserved. Finally, after the removal of the entire mass, the left kidney's hilar lymph node was dissected and along with the mass resection, the specimens were sent for pathologic examinations. Macroscopic examination of the left adrenal mass resection showed one capsulated brown rubbery mass (15 × 11 × 5 cm and 1519 gs), with a soft yellowish heterogeneous appearance and necrotic areas on cut sections. In histopathologic report, the diagnosis of Adrenocortical carcinoma was made. Hilar lymph node of kidney
consisted of one piece of unremarkable fibrofatty tissue. (1.5 × 1 × 0.5 cm).
Conclusion: Adrenal cortical carcinoma, also called adrenocortical carcinoma or ACC, is a rare high-grade malignant tumor with the estimated incidence of about 0.6 to 1.6 per million population, annually. This tumor can be hormonally active or inactive and can present in both men and women, while hormonally active tumors are more frequent in women. Cushing's syndrome secondary to elevated cortisol levels is the most common clinical symptom of hormonally active tumors. Other symptoms of hormonally active tumors include virilization or feminization and Conn's syndrome. Hormonally inactive tumors present palpable masses, abdominal pain or metastasis. Although the tumor in this case was also hormonally active in laboratory evaluation, it mainly presented as a palpable abdominal mass. ACCs are usually detected by their large sizes and irregular margins, with necrotic areas, central hemorrhages and variable contrast enhancements observed in their CT scan studies. Calcification has been reported in 30 % of these tumors. Local invasion into the renal vein, IVC, and liver is relatively common. Metastasis to local lymph nodes, lungs, bones, and liver can also occur, with hepatic metastases being predominantly hyper vascular. As Pheochromocytoma can have similar imaging appearances, in order to differentiate the type of tumor, we should use histological, biochemical, and functional tests. In fact, the main diagnostic features of pheochromocytoma are clinical symptoms and laboratory findings. In pheochromocytoma CT scan, large, heterogeneous masses with significant necrotic and cystic areas and considerable enhancement are usually observed. Octreotide (Somatostatin) scans are also positive in about 70 % of pheochromocytomas, which is a helpful finding. Malignant pheochromocytoma usually
metastases to the lungs, bones, and liver. However, none of the imaging methods, such as CT, MRI or nuclear studies can definitively differentiate adrenocortical carcinoma from pheochromocytoma. Metomide has recently been introduced as a radiotracer in PET and SPECT studies, which are still under investigation [9]. In our case, the initial diagnosis of malignant adrenal lesion was made for the patient based on the CT scan findings. Later on, according to the patient's laboratory examinations (Table 1) and Octreotide scan, adrenocortical carcinoma was suspected, with the pathology results confirming this diagnosis, which puts emphasis on the role of clinical history, lab data and nuclear imaging for a proper approach to adrenal lesions.