Epithelioid angiomyolipoma is a recently described rare variant of renal angiomyolipoma. It can occur in patients with or without tuberous sclerosis. We report the imaging findings of a case of epithelioid angiomyolipoma that showed the presence of fatty tissue undifferentiated from the typical angiomyolipoma at the beginning. After partial nephrectomy, tumour recurrence occurred two years later, presenting as completely solid tumours with no adipose tissue, and with invasion into the psoas muscle and left adrenal gland. Differentiation of this tumour from renal cell carcinoma is difficult. Both the radiologist and surgeon should be aware of the existence of this tumour and its potentially malignant behaviour.
Aged ; Angiomyolipoma ; diagnosis ; pathology ; surgery ; Carcinoma, Renal Cell ; diagnosis ; Diagnosis, Differential ; Female ; Humans ; Kidney ; pathology ; Kidney Neoplasms ; diagnosis ; pathology ; surgery ; Neoplasm Recurrence, Local ; pathology ; Tomography, X-Ray Computed

Adenocarcinoma, Clear Cell ; metabolism ; pathology ; surgery ; Adult ; Carcinoma ; metabolism ; pathology ; Carcinoma, Mucoepidermoid ; metabolism ; pathology ; Carcinoma, Renal Cell ; metabolism ; pathology ; secondary ; Diagnosis, Differential ; Humans ; Keratins ; metabolism ; Male ; Nasal Cavity ; Nose Neoplasms ; metabolism ; pathology ; surgery ; S100 Proteins ; metabolism

Carcinoma, Medullary ; pathology ; Carcinoma, Renal Cell ; diagnosis ; metabolism ; pathology ; radiotherapy ; surgery ; Diagnosis, Differential ; Humans ; Keratins ; metabolism ; Kidney Neoplasms ; diagnosis ; metabolism ; pathology ; radiotherapy ; surgery ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neoplasms, Squamous Cell ; pathology ; Nephrectomy ; Radiotherapy, Adjuvant

Adenocarcinoma, Follicular ; Adult ; Carcinoid Tumor ; metabolism ; pathology ; Carcinoma, Renal Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Keratin-7 ; metabolism ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Mucin-1 ; metabolism

Carcinoma, Renal Cell ; metabolism ; pathology ; surgery ; Cytokines ; metabolism ; Diagnosis, Differential ; Humans ; Immunohistochemistry ; Kidney ; chemistry ; pathology ; surgery ; Kidney Diseases, Cystic ; metabolism ; pathology ; surgery ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Nephrectomy

Adenoma, Oxyphilic ; metabolism ; pathology ; surgery ; Cadherins ; metabolism ; Carcinoma, Renal Cell ; metabolism ; pathology ; surgery ; Catheter Ablation ; Diagnosis, Differential ; Humans ; Keratins ; metabolism ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Male ; Middle Aged ; Neoplasms, Multiple Primary ; metabolism ; pathology ; surgery ; Parvalbumins ; metabolism ; S100 Proteins ; metabolism

The inflammatory myofibroblastic tumor (IMT), also knowns as inflammatory pseuduotumor, is a soft tissue lesion of unknown etiology. In the urogenital tract, IMT mainly affects the urinary bladder or prostate, but rarely the kidney. It has been considered as a nonneoplastic reactive inflammatory lesion, but nowadays, it is regarded as a neoplasm due to its high recurrence rate and metastasis. We describe a case of a 61-yr-old woman that had originally been misdiagnosed as renal cell carcinoma, which was pathologically revealed to be an IMT.
Actins/metabolism ; Carcinoma, Renal Cell/diagnosis/pathology ; Diagnosis, Differential ; *Diagnostic Errors ; Female ; Granuloma, Plasma Cell/*diagnosis/pathology/surgery ; Humans ; Kidney Neoplasms/*diagnosis/pathology ; Magnetic Resonance Imaging ; Middle Aged ; Tomography, X-Ray Computed ; Vimentin/metabolism

OBJECTIVE: To investigate and summarize the clinicopathological features, immunophenotype, differential diagnosis and prognosis analysis of mucinous tubular and spindle cell carcinoma (MTSCC). METHODS: The data of thirteen cases of MTSCC were retrospectively analyzed, the clinical and pathological characteristics and immunohistochemical expression were summarized, and fluorescence in situ hybridization was detected. RESULTS: Among the thirteen patients, four were males and nine females, with a male-to-female ratio of 1 ∶2.25. The average age was 57.1 years, ranging from 39 to 78 years. The maximum diameter of the tumor was 2-12 cm. All cases had no symptoms, and were accidentally discovered, 3 cases underwent partial renal resection, 10 cases underwent radical renal resection, 9 cases were located in the left kidney, and 4 cases were located in the right kidney. Most of the cases showed the classical morphological changes, with 11 cases of nuclear grading [World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading system] being G2 and 2 cases being G3. There were 6 cases of stage PT1a, 3 cases of PT1b, 2 cases of PT2a, and 1 case of PT2b and 1 case of PT3a. The positive rates of immunohistochemical staining were: vimentin, AE1/AE3, α-methylacyl-CoA racemase (αMACR) and cytokeratin (CK) 8/18, 100% (13/13); CK7, 92.3% (12/13); epithelial membrane antigen (EMA), 92.3% (12/13); CK20, 46.2% (6/13); CD10, 30.8% (4/13); synaptophysin (Syn), 7.7% (1/13); chromogranin A (CgA), CD57, WT1 and Ki-67, 0 (0/13), and fluorescence in situ hybridization showed that no trisomy of chromosomes 7 and 17 were observed in any of the cases. The follow-up period was 6 months to 7 years and 6 months, 2 cases died after lung metastasis (one with ISUP/WHO grade G3, one with necrosis), and the remaining 11 cases had no recurrence and metastasis. CONCLUSION MTSCC is a unique type of low-grade malignancy kidney tumor, occurs predominantly in females, widely distributed in age, the current treatment method is surgical resection, and cases with necrosis and high-grade morphology are prone to recurrence and metastasis, although most cases have a good prognosis, but they still need close follow-up after surgery.
Humans ; Male ; Female ; Middle Aged ; Kidney Neoplasms/surgery* ; Carcinoma, Renal Cell/diagnosis* ; In Situ Hybridization, Fluorescence ; Retrospective Studies ; Adenocarcinoma, Mucinous/pathology* ; Kidney/pathology* ; Prognosis ; Necrosis

OBJECTIVETo study the pathologic features and immunophenotype of 3 cases of melanotic epithelioid clear cell tumor of kidney.

METHODSMore than 2000 cases of renal tumors were retrospectively reviewed. Three cases of melanotic epithelioid clear cell tumor were identified. Immunohistochemical study was carried out using the paraffin-embedded tissue samples. Electron microscopy was also performed in 1 case.

RESULTSAmongst the 3 cases studied, the male-to-female ratio is 1:2. Histologically, 2 cases showed a clear cell carcinoma-like pattern. Papillary structures covered by clear cells and eosinophilic cells were observed in 1 case. Immunohistochemical study showed that the tumor cells in all cases expressed HMB 45. Two of them were also positive for Melan A. The staining for epithelial markers and S-100 protein was negative. Melanosomes were not identified by ultrastructural examination.

CONCLUSIONSMelanotic epithelioid clear cell tumor is a rarely seen neoplasm of kidney. There are some histologic overlaps with renal cell carcinoma, epithelioid angiomyolipoma and melanoma. Immunohistochemical study is useful in confirming the diagnosis. The tumor represents a morphologic variant of epithelioid angiomyolipoma.

Adolescent ; Adult ; Angiomyolipoma ; metabolism ; pathology ; surgery ; Carcinoma, Renal Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Epithelioid Cells ; metabolism ; pathology ; Female ; Follow-Up Studies ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; MART-1 Antigen ; metabolism ; Male ; Melanoma-Specific Antigens ; metabolism ; Retrospective Studies

OBJECTIVETo investigate the clinicopathological features, histogenesis and prognosis of mucinous tubular and spindle cell carcinoma (MTSCC).

METHODSFive MTSCCs were studied with histochemical, immunohistochemical staining, electron microscopy, and review of the related literatures.

RESULTSFour cases of MTSCC were females and one was male. Three patients presented with flank discomfort and two were incidentally found with health examination. In gross examination, the tumors were circumscribed. The cut surface was solid, gray-white, yellow or red. Necrosis was present in one case of high-grade MTSCC. Microscopically, low-grade MTSCC was mainly consisted of tubular, spindle cell and mucinous stroma with relatively bland morphology, and mitoses were rare. While in the high-grade area of one case, the cells were spindle or polymorphic with severe atypia and high mitotic activity, without mucinous stroma and tubular structure. Mucin was positive for Alcian blue. The neoplastic cells were positive for vimentin (5/5), CKpan (5/5), CK7 (5/5), CK19 (5/5), 34betaE12 (1/5), EMA (5/5), E-cadherin (3/5), CD10 (1/5), P504S (5/5), and CAM5.2 (5/5). The Ki-67 index was low (< or = 5%) in the low-grade component, while it was high (15%) in the high-grade component. Ultrastructural study showed short microvilli along glandular lumens. The nuclear membrane was focally invaginated. Four cases were followed up for 3 to 52 months, and recurrence and metastasis were not found.

CONCLUSIONSMTSCC occurs predominantly in females and it is a rare kidney neoplasm. Most of MTSCCs are low-grade and the prognosis is relatively good. However, the patients of high-grade MTSCC should be closely followed up.

Adenocarcinoma ; metabolism ; pathology ; surgery ; Adenocarcinoma, Mucinous ; metabolism ; pathology ; surgery ; Adult ; Carcinoma ; metabolism ; pathology ; surgery ; Carcinoma, Medullary ; pathology ; Carcinoma, Renal Cell ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Humans ; Keratins ; metabolism ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Leiomyosarcoma ; metabolism ; pathology ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Nephrectomy ; Racemases and Epimerases ; metabolism ; Vimentin ; metabolism