Kidney tumor

Adult renal cell carcinoma - rare

Mucinous tubular and spindle cell carcinoma



Last staff update: 27 March 2024 (update in progress)

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PubMed Search: Mucinous tubular and spindle cell carcinoma

Aida Valencia, M.D.
J. Cody Craig, M.D.
Page views in 2024 to date: 2,573
Cite this page: Valencia A, Gordetsky JB, Craig JC. Mucinous tubular and spindle cell carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/kidneytumormalignantmucinoustubular.html. Accessed March 28th, 2024.
Definition / general
  • Distinct polymorphic, malignant renal cell neoplasm composed of bland anastomosing tubules, spindle cell areas and myxoid stroma / extracellular mucin
Essential features
Terminology
  • Historic terminology not recommended by WHO 2022
    • Low grade tubular mucinous renal neoplasm
    • Low grade collecting duct carcinoma
    • Low grade myxoid renal epithelial neoplasm with distal nephron differentiation
Epidemiology
Sites
  • Kidney
Pathophysiology
Etiology
  • Unknown
Clinical features
  • Most cases are asymptomatic
  • Incidental finding on imaging
Diagnosis
Radiology description
  • Majority are homogeneous
  • Small subset may show cystic changes, which is more commonly seen in papillary renal cell carcinoma (RCC)
  • Typically isodense or hypodense on unweighted CT
  • Hyperintense on T2 due to extracellular mucin
  • Appears unencapsulated
  • References: Br J Radiol 2021;94:20210548, Abdom Radiol 2021;46:5250
Radiology images

Images hosted on other servers:
Isodense mass in the renal medulla

Isodense mass in the renal medulla

Hyperintensity on T2 weighted image

Hyperintensity on T2 weighted image

Prognostic factors
Case reports
Treatment
  • Surgical excision is the mainstay of treatment
  • Selected cases received adjuvant therapy with tyrosine kinase inhibitors and PD-1 inhibitors (Clin Genitourin Cancer 2019;17:268)
Gross description
Gross images

Images hosted on other servers:

Cut surface with focal hemorrhage

Frozen section description
  • Elongated tubules with low grade epithelial lining merging with areas of low grade spindled cells in a myxoid background
  • Extracellular mucin may be present
Microscopic (histologic) description
Microscopic (histologic) images

Contributed by J. Cody Craig, M.D., Aida Valencia, M.D., Jennifer B. Gordetsky, M.D. and @katcollmd on Twitter
Bland tubules and spindle cells

Bland tubules and spindle cells

Whorled tubules

Whorled tubules

Bland cuboidal and spindle cells

Bland cuboidal and spindle cells

Compact tubules

Compact tubules

Elongated tubules

Elongated tubules


Bland spindle cells

Bland spindle cells

Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma

Mucinous tubular and spindle cell carcinoma


PAX8

PAX8

CK7

CK7

p504s/AMACR

p504s / AMACR

Virtual slides

Images hosted on other servers:
Mucinous tubular and spindle cell carcinoma

Mucinous tubular and spindle cell carcinoma

Electron microscopy description
Molecular / cytogenetics description
Molecular / cytogenetics images

Images hosted on other servers:
Most common genetic alterations

Most common genetic alterations

SNP Array Analysis

SNP array analysis

Sample pathology report
  • Kidney, right, radical nephrectomy:
    • Mucinous tubular and spindle cell carcinoma, 3 cm (see comment)
    • Organ confined
    • Margins negative for tumor
    • No tumor necrosis identified
    • No sarcomatoid or rhabdoid features identified
    • No metatasis to lymph nodes
    • Pathologic stage: pT1a pN0 pMx
    • Comment: The specimen shows a kidney composed of low grade tubules merging with areas of spindled cells in a myxoid stroma. No well formed papillary areas are present. Immunohistochemical stains show positivity for PAX8, CK7, racemase and vimentin.
Differential diagnosis
Board review style question #1
Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma


A patient undergoes a partial nephrectomy for a 4 cm renal mass. The above tumor is seen on H&E examination. This tumor should show which immunophenotype?

  1. PAX8+, BAP1 loss, calretinin+, WT1+
  2. PAX8+, CA9+, CD10+, CK7-
  3. PAX8+, CK7+, vimentin+, racemase+
  4. PAX8+, TTF1+, CK7+
Board review style answer #1
C. PAX8+, CK7+, vimentin+, racemase+. The images show a mucinous tubular and spindle cell carcinoma, which should show positive staining for PAX8, CK7, racemase and vimentin. Answer D is incorrect because this immunophenotype is more consistent with metastatic thyroid cancer. Answer B is incorrect because this immunophenotype is more consistent with a clear cell renal cell carcinoma. Answer A is incorrect because this immunophenotype is more consistent with mesothelioma.

Comment Here

Reference: Mucinous tubular and spindle cell carcinoma
Board review style question #2
Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma Mucinous tubular and spindle cell carcinoma


Which of the following features would be most helpful in distinguishing a mucinous tubular and spindle cell carcinoma from a renal cell carcinoma with sarcomatoid features?

  1. PAX8+, CK7+, vimentin+, racemase+
  2. Presence of foamy macrophages
  3. Retained FH and SDHB expression on IHC
  4. VHL mutation on molecular studies
Board review style answer #2
D. VHL mutation on molecular studies. VHL mutations are not found in mucinous tubular and spindle cell carcinomas. This would be more consistent with a clear cell renal cell carcinoma. Answer A is incorrect because this immunophenotype can be found in papillary renal cell carcinoma. Answer C is incorrect because this immunophenotype excludes an SDHB deficient or an FH deficient RCC but many other renal cell neoplasms can have this finding. Answer B is incorrect because mesothelial tumors will express both CK5/6 and D2-40.

Comment Here

Reference: Mucinous tubular and spindle cell carcinoma
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