Intraglomerular metastases. Report of two cases

Severe Acute Kidney Injury Due to Intraglomerular Melanoma: A Case Report

Metastatic disease in the kidney is relatively uncommon compared to other body sites. In most cases it presents as an unilateral and unifocal mass in the tubulointerstitial region. Intraglomerular metastases are even rarer, and their diagnosis is hampered by the limitation of imaging techniques to detect them. We describe the finding of intraglomerular metastases in a patient affected by a malignant melanoma considered to be in partial remission, with no evidence of melanoma progression on the previously performed computed tomography (CT) scan. This patient developed rapidly progressive kidney, failure, proteinuria and hematuria with dysmorphic red blood cells in the urine sediment. Kidney biopsy showed a marked crescentic proliferation caused by tumor cells, which even invaded the proximal convoluted tubule. Melanoma cells were also found in the lumina of the glomerular capillaries, distending their basement membranes. Our case describes the histologic and electron microscopic findings of this form of intraglomerular metastasis and reminds us of its inclusion in the differential diagnosis of rapidly progressive kidney failure.

Intraglomerular micrometastasis of squamous cell carcinoma

Intraglomerular metastasis is a rare manifestation of disseminated malignancies. We present here a case of intraglomerular metastatic carcinoma diagnosed as an incidental finding on a kidney biopsy in a 62-year-old male presenting with acute renal failure and metastatic penile squamous cell carcinoma. A proliferative lesion composed of highly atypical epithelial cells was found within a capillary loop and adjacent urinary space of an isolated glomerulus, which was immunoreactive for markers of squamous cell carcinoma. This case is a reminder that circulating cancer cells can occasionally lodge in glomeruli and appear as micrometastasis in kidney biopsies performed for the evaluation of renal dysfunction.

Intraglomerular crescentic metastases of malignant melanoma

We describe here a patient with a metastatic malignant melanoma displaying crescentic lesions in the glomeruli. A 64-year-old woman was referred to our hospital because of a sudden increase of serum creatinine. Clinical diagnosis suggested rapidly progressive glomerulonephritis. Renal biopsy revealed diffuse crescentic lesions containing metastatic melanoma cells. These cells were also seen in the glomerular capillary lumina and tubules, and a few scattered tumor cells were also present in the interstitium. Glomerular metastasis is a very rare entity. To the best of our knowledge, this patient is the first to be described in the English language literature showing intraglomerular metastasis of malignant melanoma as demonstrated by needle biopsy and is only the second patient with intraglomerular metastasis presenting with acute renal failure.

Lymphomas diagnosed by percutaneous kidney biopsy

BACKGROUND

Occult renal lymphoma clinically mimicking renal medical disease constitutes a diagnostic challenge to nephrologists, radiologists, and renal pathologists. The clinical and radiological findings, mostly nonspecific or inconclusive, seldom obviate the need for a kidney biopsy.

METHODS AND RESULTS

We report 5 new cases of diffuse bilateral renal lymphoma diagnosed by percutaneous kidney biopsy, all presenting with acute renal failure (ARF) of unknown cause. Three cases showed an interstitial and 2 an intraglomerular/intravascular type of lymphomatous infiltration. All tumors were of B-cell lineage. Our cases add to 50 similar cases reported since 1980. Considering all 55 cases together, 39 (87%) of the 44 cases with interstitial and 5 of 11 (45%) of those with intraglomerular lymphoma presented with ARF. In contrast, 5 of 10 cases with intraglomerular but none with interstitial infiltration presented with nephrotic range proteinuria. All but 2 cases (95%) with ARF and interstitial lymphoma but none with ARF and intraglomerular lymphoma showed bilaterally enlarged kidneys. Signs of extrarenal lymphomatous involvement were detected in 24 cases (44%) at the time of kidney biopsy or shortly thereafter. However, in only 10 cases (18%), all with interstitial lymphoma, was a tumor suspected prior to biopsy, mainly based on radiographical evidence of enlarged kidneys.

CONCLUSION

Both types of diffuse bilateral renal lymphoma may clinically mimic renal medical disease. ARF in interstitial and in intraglomerular lymphoma may be due to increased intrarenal pressure and intraglomerular obstruction, respectively. Percutaneous kidney biopsy provides the most expedient means of establishing the diagnosis. Differential diagnosis includes interstitial nephritis and proliferative glomerulonephritis.

Intraglomerular metastasis: a necropsy study

Intraglomerular metastasis is a rare phenomenon. Four cases are reported here. The primary malignancies in these four cases were squamous cell carcinoma of the lung, adenocarcinoma of pancreas, haematological malignancy with a malignant intrapulmonary teratoma, and undifferentiated pleural mesothelioma. There was no significant renal functional impairment in any case except for mild proteinuria in one. Histopathology showed tumour cells in the mesangium, in the glomerular tufts replacing the endothelial cells, as well as in an extracapillary location replacing the parietal cells. In one case, tumour cells formed crescent-like structures. Such tumour deposits were better appreciated with special stains. The presence of intraglomerular metastasis indicates dissemination of the malignancy and hence a poor prognosis even though there is no significant impairment of renal function.

Intracapillary glomerular metastases in a nephrectomy specimen removed for ipsilateral renal cell carcinoma

A case of intraglomerular metastases observed in a nephrectomy specimen removed for primary renal cell carcinoma is reported. The intraglomerular metastases arose by dissemination of malignant cells into the systemic circulation via invasion of the renal veins. Intraglomerular metastases are therefore an indicator of malignant dissemination which in turn should be associated with a poor prognosis. It is recommended that in nephrectomies undertaken for primary renal cell carcinoma at least one random block of renal cortex should be examined to confirm or exclude intraglomerular metastases.

Extracapillary tumourous metastatic crescents in glomeruli of the kidney

This report describes intraglomerular tumor cell metastases, as a rare pathologic observation. Specimens of one hundred autopsy cases (each having extrarenal carcinoma) were examined by light microscopy, and in seven of them metastatic crescents were found in the urinary space of the Bowman's capsule. The capsule itself and the layer of the parietal epithelium seemed to be intact. Glomeruli with metastases in five cases were near or inside the extraglomerular metastatic tumor mass. This phenomenon must be distinguished from metaplastic transformation of the glomerular capsular epithelium.