
==== Front
Int J Surg Case Rep
Int J Surg Case Rep
International Journal of Surgery Case Reports
2210-2612
Elsevier

S2210-2612(24)00974-X
10.1016/j.ijscr.2024.110193
110193
Case Report
Mucinous tubular and spindle cell carcinoma very rare variant kidney cancer: Case report
Tamir Kumlachew Tilahun tastu211@gmail.com
⁎
Ademe Samuel Almaw Samuelyeab25@gmail.com

Mikru Admassu Melaku admax2009@gmail.com

Jiffar Amanuel Damie amanuel.damie@aau.edu.et

Hamza Abdurrhman Kedir abdurrhmanhamza@gmail.com

Ayalew Zekarias Seifu zekariasseifu123@gmail.com

Addis Ababa University, College of Health Sciences, School of Medicine, Ethiopia
⁎ Corresponding author at: Addis Ababa University, College of Health Sciences, School of Medicine, PO Box: 9086, Ethiopia. tastu211@gmail.com
22 8 2024
10 2024
22 8 2024
123 1101931 6 2024
13 8 2024
15 8 2024
© 2024 The Authors
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction and importance

Mucinous Tubular and Spindle Cell Carcinoma (MTSCC) of the kidney is a rare variant, first classified by WHO in 2004 classification of RCC. MSCC has distinct morphology and immunohistochemistry unlike challenging previous renal tumor classifications. Despite its rarity, MTSCC diagnosis is important due to its unique characteristics.

Case presentation

We present a 56-year-old female with a decade-long history of right-side abdominal pain and swelling. Physical examination revealed a 15*10 cm mass on the right flank. Imaging indicated a heterogeneously enhancing right renal mass, diagnosed as localized right Renal Cell Carcinoma (RCC). A radical nephrectomy was performed, and the biopsy confirmed MTSCC. The patient was discharged on the 6th post-op day, with no adjuvant treatment due to localized tumors.

Clinical discussion

MTSCC, constituting <1 % of RCC, primarily affects females (1:3–4) with an indolent course. Radical nephrectomy is the preferred treatment, offering a favorable prognosis. However, a small percentage may experience metastasis, necessitating mandatory follow-up.

Conclusion

MTSCC of the kidney is a rare RCC variant with an excellent prognosis. Surgical excision, specifically radical nephrectomy, is the mainstay of treatment. Adjuvant therapy may not be required for localized tumors. Postoperative follow-up is crucial, despite the rare risk of metastasis reported in some cases.

Highlights

• Mucinous tubular and spindle cell carcinoma of the kidney is a rare variant of renal cell carcinoma.

• Mucinous tubular and spindle cell renal cell carcinoma is a low-grade carcinoma with an indolent natural course.

• The main mode of management for any type of renal cell carcinoma is surgical excision.

• The majority of diagnoses of mucinous tubular and spindle cell carcinoma of the kidney are done by pathology mainly morphology but if there is any difficulty in diagnosing via morphology we can do immunohistochemical staining and FISH technique.

• The prognosis is excellent with long-term survival and a low risk of recurrence and metastasis.

Keywords

Mucinous tubular and spindle cell carcinoma
Radical nephrectomy
Renal cell carcinoma
Case report
Abbreviations

MTSCC mucinous tubular and spindle cell carcinoma

WHO World Health Organization

RCC renal cell cancer

AMACR a-methyl acyl CoA racemase

CK cytokeratin

EMA epithelial membrane antigen

PAX8 Paired-box gene 8

CD a cluster of differentiation

CAM cellular adhesion molecule

SCARE surgical case report

ECOG Eastern Cooperative Oncology Group
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pmc1 Introduction

MTSCC is a rare variant of RCC that accounts for <1 % of RCC. The mean age for the diagnosis is 13 to 82 years of age with female predominance (1:3–4) and an indolent course [1]. The clinical presentation of the RCC is mostly asymptomatic and it is called a radiologist tumor because the diagnosis is made when imaged for other conditions and if they present with symptoms they present with flank pain or hematuria. The diagnosis of MSCC is pathological and Histologically and MTSCC is composed of low-grade tightly packed tubular cells and braided spindle cells with myxoid stroma. Most MTSCC is diagnosed by morphology alone but in some cases, it can be challenging to differentiate from a solid variant of papillary RCC, sarcomatoid RCC, or myoid-predominant angiomyolipoma with morphology alone and need immunohistochemical staining [2].

On immunohistochemistry, MTSCC shows positive reactions for AMACR, CK7, CK19, EMA, PAX8, vimentin, and E-cadherin but still, there is overlapping positivity and negativity with immunohistochemical staining and need chromosomal study. Copy number analyses can help establish a diagnosis in challenging cases or core biopsies since these are associated with multiple chromosomal losses involving chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22 [2].

MTSCC is often negative for proximal tubule markers CD10 and CD15, but some cases show weak positivity [3]. A small percentage of patients can present with aggressive clinical behavior. The presence of the following features in pathology shows adverse features: necrosis, solid growth, single file infiltration, sarcomatoid transformation, lymphovascular invasion, and increased mitoses [1]. The main management for MTSCC is surgical excision of the tumor but for locally advanced or metastatic cases, systemic treatment is needed even though the ideal systemic treatment for MTSCC is unknown because most trials are done on the clear cell RCC. Systemic therapies that were proven efficacious against clear cell RCC have been used for metastatic MTSCC [4].

The work has been reported in line with the SCARE criteria [5].

2 Case presentation

56 years-old female patient was referred to our Hospital and seen at the urology outpatient department with a complaint of right side flank pain and swelling of 15 years' duration which has progressively worsened over the last 01-year duration. The pain is a dull aching type of pain with associated back pain. The swelling was initially small and gradually increased to attain the current size. p/e shows an ECOG score of one with 10*15 cm mass on the right flank area which also included the right upper and lower quadrant which is a smooth surface, non-tender, immobile and firm mass.

Laboratory results of CBC, RFT, U/A, and serum electrolyte results are within the normal range.

Abdominal u/s showed a huge solid renal mass and an abdominopelvic CECT scan was ordered to further characterize and stage the tumor. CECT scan showed 10*17 cm heterogeneously enhancing right renal mass which has no local invasion, lymph node enlargement, or lower lung metastasis (Fig. 1). Surgical management was planned and the right radical nephrectomy was done uneventfully. The intraoperative finding was a huge well circumscribed right renal mass which occupies most of the right side upper and lower quadrants up to the level of iliac crest. The mass that is well circumscribed is removed after opening the Gerota fascia because the mass is huge to excise via extra-Gerota fascia after controlling the hilum (Fig. 3).Fig. 1 A and B: show a coronal image.

C: cross-sectional image.

D: sagittal image.

The above image shows a pre-operative contrast-enhanced abdominopelvic CT scan of the patient with a huge right renal mass.

Fig. 1

The patient was discharged from the ward on the 6th post-operative day without complication.

The biopsy result showed a tumor composed of a bland tubular structure composed of cuboidal and focal clear cells that transition to the spindle cells with histologic grade 2 and tumor cells limited to the kidney and no feature of sarcomatoid, rhomboid histology. Has no lymphovascular invasion and there is 30 % tumor necrosis on the histology. The biopsy has a negative margin with no regional lymph node involvement.

The conclusion of the biopsy shows PT2bPNXMX mucinous tubular and spindle cell renal cell carcinoma, grade 2, PT2B, NX, MX (Fig. 2).Fig. 2 Intraoperative picture during right radical nephrectomy.

Fig. 2

Fig. 3 Pathologic picture with mucinous tubular and spindle cell.

Fig. 3

She is on follow up and regular follow-up with imaging is mandatory to detect local recurrence or metastasis according to the RCC follow-up guideline.

3 Discussion

MTSCC is a rare variant of RCC which accounts for <1 % of RCC with distinct morphologic and cytogenetic characteristics.it is more prevalent in the female population [1,3,4] with an age range of 13 to 82 years of age. it has an indolent course with a good prognosis [1]. MTSCC was first described in the 2004 World Health Organization classification of tumors of the kidney [3] Imaging can only show the presence of solid renal mass otherwise specific type of histology is confirmed by pathology. Majority of the MTSCC is diagnosed by pathological morphology alone but in challenging cases immunohistochemistry staining and FISH technique to detect the chromosomal loss might be needed.

Microscopically, these tumors consist of closely packed, small, elongated tubules that are separated by a light-colored mucinous stroma. The parallel arrangement of these tubular structures frequently exhibits a spindle cell configuration, occasionally resembling leiomyoma or sarcoma.

The main management for RCC is surgical excision which is either partial or radical nephrectomy depending on the stage and size of the tumor. After surgical excision, regular follow-up is mandatory with cross-sectional imaging of the chest and abdominopelvic with targeted imaging based on the symptoms even though the nature of the MTSCC is a low-grade tumor with an indolent course. The duration of follow-up is mostly up to 3 to 5 years since the risk of recurrence is low-risk and further follow-up depends on the patient's wish, age, and life expectancy of the patient. However, there is a subset of patients who may exhibit locally advanced disease upon presentation, underscoring the importance of thorough monitoring, even in instances of localized tumors. The exact postoperative recurrence rate for MTSCC remains indeterminate because of the rare nature of the tumor [6].

Features such as necrosis, solid growth, single-file infiltration, sarcomatoid transformation, lymphovascular invasion, and increased mitotic activity are indicative of the existence of metastatic and highly aggressive disease [2,7]. Generally, the prognosis is excellent with few reported cases of metastatic MTSCC [8]. For our patient, a right radical nephrectomy was done because of the localized nature of the tumor.

4 Conclusion

MTSCC is a rare variant of RCC with few reported cases. Radical nephrectomy is the main mode of management for RCC. MTSCC is a pathological diagnosis and pathologists play a key role in diagnosing it. Long-term follow-up is mandatory even though it is a low-grade tumor.

Patient (parent's) consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

Ethical approval was provided by the author's institution.

Funding

N/A.

Guarantor

1. Dr Admassu Melaku Mikru (MD, Assistant Professor of Urology): operated the patient, conceptualization, reviewed, and edited the final manuscript.

2. Dr Amanuel Damie Jiffar (MD, Assistant Professor of Pathology): diagnosed the histology and reviewed the final manuscript.

Research registration number

N/A.

CRediT authorship contribution statement

1. Dr Kumlachew Tilahun Tamir (MD, Urology Resident): diagnosed the patient, conceptualization, methodology, manuscript writing, and submission and followed the patient.

2. Dr Samuel Almaw Ademe (MD, Assistant Professor of General Surgery and Urology Fellow): assisted the operation and followed the patient, conceptualization, reviewed, and edited the final manuscript.

3. Dr Admassu Melaku Mikru (MD, Assistant Professor of Urology): operated the patient and reviewed the final manuscript.

4. Dr Amanuel Damie Jiffar (MD, Assistant Professor of Pathology): diagnosed histology and reviewed the final manuscript.

5. Dr Abdurrhman Kedir Hamza (MD, pathology resident): Assisted histologic diagnosis and edited the case report.

6. Dr Zekarias Seifu Ayalew (MD, Internist):reviewed the manuscript and edited the case report.

Declaration of competing interest

No competing financial interests exist.
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References

1 Trpkov K. Hes O. Williamson S.R. Adeniran A.J. Agaimy A. Alaghehbandan R. New Developments in Existing WHO Entities and Evolving Molecular Concepts: The Genitourinary Pathology Society (GUPS) Update on Renal Neoplasia. Vol. 34, Modern Pathology 2021 United States & Canadian Academy of Pathology (1392–1424 p.)
2 Bhardwaj N. Parkhi M. Chatterjee D. Singh S.K. Mucinous tubular and spindle cell carcinoma of the kidney Autops Case Reports. 13 2023 2 4
3 Natarajan R. Kanchan Murhekar Anand Raja Shirley Sundersingh A case report: mucinous tubular and spindle cell carcinoma of kidney with spindle cell predominance mimicking mesenchymal tumour J Kidney Cancer VHL. 9 4 2022 10 13 36381239
4 Fuchizawa H. Kijima T. Takada-Owada A. Nagashima Y. Okazaki A. Yokoyama M. Metastatic mucinous tubular and spindle cell carcinoma of the kidney responding to nivolumab plus ipilimumab IJU Case Reports. 4 5 2021 333 337 34497997
5 Sohrabi C. Mathew G. Maria N. Kerwan A. Franchi T. Agha R.A. The SCARE 2023 guideline: updating consensus Surgical CAse REport (SCARE) guidelines Int. J. Surg. 109 5 2023 1136 1140 37013953
6 Ling C. Tan R. Li J. Feng J. Mucinous tubular and spindle cell carcinoma of the kidney: a report of seven cases BMC Cancer 23 1 2023 1 8 36597025
7 Simon R.A. di Sant’agnese P.A. Palapattu G.S. Singer E.A. Candelario G.D. Huang J. Mucinous tubular and spindle cell carcinoma of the kidney with sarcomatoid differentiation Int J Clin Exp Pathol [Internet]. 1 2 2008 180 184 Available from: http://www.ncbi.nlm.nih.gov/pubmed/18784804%0Ahttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC2480554 18784804
8 Chan T.Y. World Health Organization classification of tumours: pathology & genetics of tumours of the urinary system and male genital organs Urology 65 1 2005 214 215
