Renal mucinous and tubular spindle cell carcinoma: a clinicopathological study of 4 cases

Mucinous Tubular and Spindle Cell Carcinoma of the Kidney with Nodal Metastasis Managed with Surgical Resection

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare renal malignancy that usually follows an indolent course. The few existing reports of metastatic MTSCC show poor response to systemic therapy. Here we describe the unusual case of a 39-yr-old male with MTSCC presenting as a large renal mass with bulky retroperitoneal lymphadenopathy managed with complete resection of disease. He has remained free of recurrence for 1 yr postoperatively. On the basis of the experience reported here, aggressive surgical resection of MTSCC with isolated nodal metastases may be considered for similar patients in the future given the historically poor response rates to systemic therapy.

Mucinous tubular and spindle cell carcinoma of the kidney: imaging features

This article describes the features on sonography, computed tomography (CT) and magnetic resonance imaging (MRI) of mucinous tubular and spindle cell carcinoma of the kidney. Six pathologically proven cases of mucinous tubular and spindle cell carcinoma of the kidney were identified (5 females, 1 male); all patients underwent preoperative imaging. The mean age of the patients was 58.5 years. Thirteen imaging studies were available for review: 2 sonograms, 1 unenhanced CT scan, 5 contrast-enhanced CT scans, 1 unenhanced magnetic resonance imaging (MRI) examination, and 4 contrast-enhanced MRI examinations. Two abdominal radiologists evaluated all images retrospectively on a PACS workstation using a standardized data collection sheet until consensus was reached. All mucinous tubular and spindle cell carcinomas presented as well-marginated, small (mean 2.6 cm, range 1.9-3.2 cm) predominantly solid masses. No intratumoral fat or calcification was identified. Unenhanced CT and MRI appearances were variable as was the degree of enhancement following intravenous contrast material administration. There was no evidence of perinephric extension, renal vein involvement or metastatic disease in any of the cases. The radiological appearance of mucinous tubular and spindle cell carcinoma is diverse and therefore indistinguishable from the more common subtypes of renal cell carcinoma.

A case of renal mucinous tubular and spindle cell carcinoma

A 33-year-old man was hospitalized for treatment of a left renal tumor. The radiological findings were consistent with those of a left renal cell carcinoma (RCC). Subsequently, a radical nephrectomy was carried out. Macroscopic examination showed that a well-demarcated tumor measuring 2.9 x 2.6 x 2.5 cm was present in the middle portion of the resected kidney. The cut surface of the tumor was grayish-white in color. Pathological examination of the resected specimen showed a mucinous tubular and spindle cell carcinoma of the kidney (MTSCC-K). MTSCC-K is a low-grade renal epithelial neoplasm that has recently been recognized as a specific entity in the World Health Organization 2004 classification of RCC. To our knowledge, 17 cases of MTSCC-K in Japan have been reported by Japanese investigators. To avoid administration of excessive adjuvant treatment to patients, pathologists and urologists should consider this newly recognized low-grade malignancy when diagnosing renal tumors.

[Papillary renal cell carcinoma spectrum]

OBJECTIVES

Significant conceptual expansion of renal cancer continues to increase. The key point to this phenomenon is based on the combination of morphology and molecular data. The result is the new 2004 WHO classification of renal tumors in adults. The apparently never ending advance in molecular genetics is constantly pushing to update recently proposed listings.

MATERIAL AND METHODS

Papillary renal cell carcinoma, considered the term in the broader sense, is the subject of this study. This histological phenotype in renal cancer, with an accelerated growth in the last times, is a good example of the never ending evolution of pathology as a clinical discipline.

RESULTS

The genetic background and the phenotype of all renal neoplasms with papillary or tubulo-papillary phenotype, or with its genetic background, some of them being very recently described entities even now under discussion is wide and heterogenous: conventional sporadic papillary carcinoma, papillary carcinomas linked to genetic syndromes (hereditary papillary carcinoma, papillary carcinoma associated to hereditary leiomyomatosis, papillary carcinoma associated to hereditary papillary thyroid carcinoma, Birt-Hogg-Dubé syndrome) or to specific genetic disorders (Xp11.2 associated papillary carcinoma), papillary carcinoma with distinct morphology (micropapillary carcinoma, inverted papillary carcinoma, papillary carcinoma with spindle cells and angulated tubules) and new renal carcinomas included within the group of papillary carcinoma (tubulo-cystic carcinoma and tubular, mucinous and spindle cell carcinoma).

CONCLUSION

Aside from the classically known histological variants, several new entities, some of them still badly delineated, are progressively enlarging the group of renal carcinomas with papillary phenotype. This growth will continue in the next times on the light of the new findings and pathologists will be main actors in this fact.