Renomedullary Interstitial Cell Tumor in the Background of a Renal Oncocytoma: A Case Report.

Renomedullary interstitial cell tumors (RMICTs) are rare benign renal tumors that arise from the renal medulla. They are rarely symptomatic and are mostly discovered incidentally. Radiologically, their co-presence ipsilaterally in the background of a larger mass introduces a miscellaneous presentation that raises the suspicion of metastatic disease. A characteristic presentation does not exist. Therefore, an individualized, patient-centered approach should be tailored depending on the nature of the presentation. We report the clinical, radiological, and histopathological presentation of a 46-year-old woman presenting with an RMICT in the background of a renal oncocytoma.

Suspected renal interstitial cell tumor causing polycythemia in two dogs.

Here we report a case series of two dogs diagnosed as renal interstitial cell tumor (RICT) accompanied by elevated serum erythropoietin level and marked polycythemia. RICT is a rare tumor in dogs, originating from renal interstitial cells. While several renal tumors such as renal lymphoma, adenocarcinoma, carcinoma, sarcoma, fibrosarcoma and nephroblastoma may cause polycythemia, polycythemia caused by RICT has never been reported in dogs. The tumors in both dogs were solitary and lied within cortex or cortico-medullary junction. Histopathology revealed spindle-shaped cells suggesting mesenchymal origin, with no mitotic figures suggesting that the tumors in both dogs were benign. Following surgical removal of the affected kidney, serum erythropoietin level and polycythemia normalized in both dogs.

Rare renaissance: Quadruple synchronous renal cell tumors in one kidney - A case report.

Multifocality in renal tumors is a rare occurrence, but not unheard of. Commonly the different foci correspond to the same histological pathology, however co-existence with other renal lesions, including both malignant and benign tumors, have also been reported. Here we present a 57-year-old male, ex-smoker who exhibited four distinct histological tumors in an ipsilateral kidney; multilocular cystic clear cell renal cell carcinoma (RCC) of low malignant potential, clear cell papillary RCC, renal oncocytoma, and renomedullary interstitial cell tumor. To our knowledge this is the first time these four tumors were found in the same patient, let alone the same kidney.

A case of renomedullary interstitial cell tumor: Radiologic-pathologic correlation.

Renomedullary interstitial cell tumor (RMICT), referred to as a medullary fibroma, is almost always asymptomatic and incidentally identified either at autopsy or upon resection of the kidney for other reasons. Although a few cases of RMICTs that are large in size and clinically symptomatic have been reported, there are few reports of RMICTs contrasting imaging findings with pathological findings. In this report, we describe a relatively large RMICT case of 3 cm in size, focusing on the radiologic-pathologic correlation.

Potential clinical implications of an incidental renomedullary interstitial cell tumor in renal allograft biopsy.

Renomedullary interstitial cell tumors (RMICTs) are often incidentally detected lesions at autopsy or resection of the kidney for other reasons. The RMICTs have not been reported in renal allograft biopsy. Overall, given the clinical implications of the differential diagnosis considered, such as morphologically similar neoplasms, interstitial fibrosis and tubular atrophy (IFTA), amyloidosis, and oxalosis, it is prudent to exclude these by an appropriate workup. Once excluded, the patients can be reassured. However, regular follow-up is recommended due to the propensity of RMICT to increase in size with age.

A case report of renal inflammatory myofibroblastic tumor and renomedullary interstitial cell tumor / 中华泌尿外科杂志

Inflammatory myofibroblastic tumor (IMT)is a potentially or low-grade malignant mesenchymal neoplasm, which is rare in clinic. Renomedullary interstitial cell tumor(RICT) is a clinically rare benign renal tumor. The combination of these two diseases in one patient has not been reported. A 25-year-old female patient was admitted to the hospital due to left back pain for 12 days and hematuria for 1 week. MRI of kidneys showed a mass in the left renal pelvis, which was considered as renal pelvic carcinoma. Urine cytopathological examination was negative. Robot-assisted laparoscopic radical left nephroureterectomy was performed. There was no tumor recurrence or metastasis during the follow-up for more than 6 months after operation.

Metastatic renal interstitial cell tumor in a dog.

Renal interstitial cell tumor (RICT) is a rare renal sarcoma of dogs that arises from renal interstitial cells. Herein we describe a RICT in an 8-y-old female Labrador Retriever dog that died after a 2-d history of lethargy and disorientation. Grossly, soft white nodules of 1-10 mm diameter were present in the renal cortex and corticomedullary junction of both kidneys, left cardiac ventricular wall, and right cerebral hemisphere. A pale-white to yellow, firm, irregular mass effaced 80% of the right pulmonary parenchyma, involving mainly the cranial and middle lobes, and the adjacent tracheobronchial lymph nodes. Histologically, the renal, myocardial, and cerebral neoplasm consisted of interlacing bundles of stellate-to-spindle cells with eosinophilic vacuolated cytoplasm and round-to-oval nuclei with finely stippled chromatin. The mitotic count was 28 per 2.37 mm2. Alcian blue stain revealed an extracellular myxomatous matrix throughout the neoplasm. Neoplastic cells had cytoplasmic immunolabeling for vimentin and cyclooxygenase 2. The pulmonary and tracheobronchial neoplasm consisted of infiltrative nodules of cuboidal epithelial cells that had a moderate amount of eosinophilic cytoplasm and round nuclei with coarsely stippled chromatin. There were 5 mitoses per 2.37 mm2. Neoplastic cells had cytoplasmic and nuclear immunolabeling for cytokeratin AE1/AE3 and thyroid transcription factor 1, respectively. Morphologic and immunohistochemical findings were consistent with a RICT with cardiac and cerebral metastases, and a pulmonary carcinoma with tracheobronchial lymph node metastasis.

[Renomedullary interstitial cell tumor: review of a rare clinical case].

Autopsy study of a 49-year-old patient demonstrates a rare kidney tumor that had a structure of a mesenchymal renomedullary interstitial tumor (RIO), which had specific characteristics. They include a predominance of the cellular component in the tumor, represented by cells with processes elements (fibroblasts, myofibroblasts), which were surrounded by collagen fibers of interstitium. Apparently, these cells can be involved in the regulation of renin and bicarbonates, the exchange of components of connective tissue (collagen fibers, proteoglycans) and hormones (estrogen, progesterone). Since these tumor cells regulate the synthesis and secretion of the substances, numerous clinical manifestations of RIO can be explained. Most likely, these include increased blood pressure, water-electrolyte disorders, hormonal disorders due to the presence of estrogen receptors, progesterone in the tumor tissue and metabolic disorders (diabetes mellitus). However, these assumptions require further clinical, morphological and immunohistochemical studies.

Renal interstitial cell tumor in a dog: clinicopathologic, imaging, and histologic features.

Renal interstitial cell tumors are benign tumors of renomedullary origin; however, malignant features have not been reported in dogs, to our knowledge. A 17-y-old spayed female Maltese dog was presented to a local animal hospital with a mass in the right abdomen. Clinicopathologic findings prior to surgery revealed renal insufficiency and anemia. Imaging revealed that the right kidney was enlarged by an amorphous mass with opaque areas, indicative of mineralization. Upon histologic examination, the mass was comprised of malignant mesenchymal cells that produced mucinous matrix. The tumor cells were positive for vimentin and COX-2, but negative for pancytokeratin; the matrix stained positively with alcian blue. Therefore, the mass was diagnosed as a renal interstitial cell tumor, with malignant features. COX-2 may be useful in the diagnosis of canine renal interstitial cell tumors, similar to its diagnostic role in humans.

Immunohistochemical characteristics of renomedullary interstitial cell tumor: a study of 41 tumors with emphasis on differential diagnosis of mesenchymal neoplasms.

Renomedullary interstitial cell tumors (RMICTs) are almost always incidentally identified either at autopsy or upon resection of the kidney for other reasons. However, rare cases that are large, resulting in a clinical mass, have been reported. The immunohistochemical phenotype of usual, incidental RMICT using modern soft tissue tumor markers is largely unknown, however, providing little information to aid in classification of larger or atypical tumors. We retrieved 41 RMICTs from 36 patients and studied pathologic characteristics including morphology, immunohistochemistry (S100, keratin AE1/AE3, smooth muscle actin, desmin, estrogen and progesterone receptors, calponin, CD34, CD35), and histochemical staining. Data collected included age, sex, tumor size, laterality, and indication for kidney examination. RMICTs (n = 41) were identified in 23 men and 13 women, with a mean age of 57 years (range, 24-83 years); tumor sizes ranged from less than 1 to 13 mm (median, 4 mm). Kidneys were resected for 32 tumors, 1 chronic pyelonephritis, 1 trauma, and 2 autopsies. All (41; 100%) had entrapped renal tubules, 5 (12%) of which included cystic or dilated tubules. Most (35; 85%) had collagenous fibers, all of which were negative for Congo red. RMICT demonstrates a largely negative immunohistochemical phenotype with weak-to-moderate labeling for smooth muscle actin and calponin that is substantially less than myofibroblastic lesions. Positive staining for estrogen and progesterone receptors is common (61%), which could overlap with mixed epithelial and stromal tumor and other entities; however, staining is typically weak. CD34 is usually negative, with occasional weak labeling, in contrast to solitary fibrous tumor.

Spiral CT diagnosis of gastric stromal tumor / 中国医学影像技术

Objective To assess CT diagnostic value of gastric stromal tumor (GST). Methods Clinical data and spiral CT findings of 20 patients with pathologically proven GST were analyzed retrospectively. Results Twenty lesions were solitary in plain CT scan image. The malignant lesions (n=9) were larger than 5.0 cm in diameter and cystic degenerations as well as necrosis were detected within the tumors, while the underlying malignant lesions (n=11) were smaller than 5.0 cm in diameter and most of them showed homogeneous density. Calcification was detected in 2 patients. On enhanced CT scan, the substantial part of the lesions was obviously strengthened. Multiplanar reformation displayed the relationship of tumor and stomach clearly. Conclusion The CT imaging features of gastric stromal tumor are characteristic. Plain CT scan and multiplanar reformation are helpful to determine the location and nature of gastric stromal tumors.

A case of renomedullary interstitial cell tumor(so-called renal medullary fibroma) / 대한비뇨기과학회지

Although fibromas are the most common renal medullary tumor identified at autopsy. their small sized and benign course make clinical detection extremely difficult. Only 9 clinical cases of renal medullary fibromas have been reported. Many fibromas of the renal medulla, previously considered as bamahomas. seemed to be composed of tumerous transformation of renomedullary interstitial calls Herein we report on a patient with huge renal medullary fibroma treated by right radical nephrectomy.

Renomedullary Interstitial Cell Tumor

We present an ultrastructure of an incidentally found renomedullary interstitial tumor also called as medullary fibroma in a 77 year-old female who had a metastatic adenocarcinoma of colon to the ureter. This tumor was a small and grayish white nodule in renal medulla, measuring 0.4 x 0.4 cm. Microscopically the tumor composed of spindle cells, with some vacuolation and intercellular collagen fibers. The electron microscopic observation of the spindle cells reveal that nuclei are spindle to oval shape and cytoplasm contain abundant rough endoplasmic reticulum, polyribosome without microfilaments and cisterna like structures supporting that the renomedullary interstitial cell tumor is renal interstitial cell origin than fibroblasts.

A Case of Interstitial Cell Tumor of Testis In Adult / 대한비뇨기과학회지

Interstitial cell tumor of testis is relatively rare, comprising only 0.8 to 1.4 percent of all testicular tumors. A 67-year-old man was admitted to our hospital with rapid growing testicular mass. He had the experience of hydrocele and many times of aspiration since childhood. On physical examination, the testicular mass (left) was hard, adult fist sized and associated with transparent cystic fluid. Under the impression of testicular tumor, orchiectomy was performed. We report this case with review of literature.