Mucinous Tubular and Spindle Cell Carcinoma of Kidney (MTSCC)

CLINICAL FEATURES

• A uncommon pattern of RCC, possible of collecting duct and possibly loop of Henle origin.

• Predominantly in females.

• Not associated with malignant behavior.

GROSS FINDINGS

• Solid, pale tan to yellow to gray-white;

• May have slight focal areas of necrosis or hemorrhage.

MICROSCOPIC FINDINGS

• Elongated branching tubules in a bubbly myxoid stroma.

• Collapsed tubules in a cord-like pattern.

• The cells are cuboidal, with scant, clear to pale, acidophilic cytoplasm and low-grade nuclear features.

• The background is mucinous with basophilia and a characteristic bubbly appearance.

IMMUNOHISTOCHEMISTRY AND SPECIAL STAINS

• Cytokeratins 18 and 19, and EMA

CYTOGENETIC STUDIES

• Consistent losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22.

REFERENCES

• AFIP, tumor of the kidney, bladder and related urinary structures, series 4