Case report
Year :
2018 |
Month :
July
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Volume :
7 |
Issue :
3 |
Page :
PC01 - PC03 |
Full Version
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Diagnostic Conundrum in a Case of Solid Papillary Renal Cell Carcinoma
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Smita Singh, Aruna Chhikara, Kiran Agarwal 1. Associate Professor, Department of Pathology, Lady Hardinge Medical College, New Delhi, India.
2. Senior Resident, Department of Pathology, Lady Hardinge Medical College, New Delhi, India.
3. Director Professor, Department of Pathology, Lady Hardinge Medical College, New Delhi, India.
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Correspondence
Address :
Smita Singh, Aruna Chhikara, Kiran Agarwal, Dr. Aruna Chhikara,
Senior Resident, Department of Pathology,
Lady Hardinge Medical College,
New Delhi-110001, India.
E-mail: arunachhikara123@gmail.com
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| ABSTRACT | | : Papillary Renal Cell Carcinoma (RCC) is the second most common carcinoma arising from the renal tubular epithelium. It comprises 10-15% of cases in surgical series. The solid variant of papillary RCC includes only those RCCs that lack true papillae but contain the characteristic immunohistochemical and genetic features of papillary RCC. Here, we present the clinical, histopathologic and immunohistochemical findings of a rare case report of solid variant of papillary RCC. A 45 years old female presented with left abdominal mass. Histopathological sections showed tumour cells arranged in tubules, trabeculae and cords with occasional interspersed long branching and angulated channels with pointed ends. Even extensive sampling of the tumour failed to reveal any papille. The differential diagnosis included solid papillary RCC (s-PRCC), Metanephric Adenoma (MA) and Collecting Duct Carcinoma (CDC). Histologically, these tumours may show overlapping features. The use of IHC markers panel comprising of CK7, EMA, Vimentin, AMACAR and WT1 can help to reach at a diagnosis. |
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Keywords
: Collecting duct carcinoma, Metanephric adenoma, Solid renal cell carcinoma |
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DOI and Others
: DOI: 10.7860/NJLM/2018/32584:2293
Date of Publishing: Jul 01, 2018
Financial OR OTHER COMPETING INTERESTS:
None. |
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Case Report |
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A 45-year-old female presented with left abdominal mass and pain for one year. Her medical history and physical examination were unremarkable except for a bimanually palpable, ballotable, firm mass measuring 9X8 cm in left lumbar region, extending into umbilical region, part of left iliac fossa and hypogastrium. Possibility of renal cell carcinoma was considered. Computed tomography scan demonstrated a large encapsulated well defined heterogeneously enhancing mass lesion measuring 8.7 x 8.3 x 7.6 cm arising from lower pole of left kidney. The right kidney and rest of the abdomen was unremarkable. After taking consent from the patient a left sided radical nephrectomy was performed.
Grossly, the kidney measured 15 x 9 x 8 cm. The cut surface showed a homogenous, tan brown well circumscribed tumour at the lower pole of the kidney measuring 9 x 8 x 6 cm. The tumour was confined within the renal capsule. Microscopically, the tumour was separated from the surrounding renal parenchyma by a thick fibrous pseudocapsule (Table/Fig 1) (a). The tumour was composed of predominantly of tubular pattern with few areas showing cells arranged in trabeculae and cords. Occasional interspersed long branching and angulated channels with pointed ends were also noticed (Table/Fig 1) (b). The Cells were cuboidal with moderate amount of eosinophilic cytoplasm, round nucleus with mild anisonucleosis and fine granular chromatin. Few cells showed prominent nucleoli. Even extensive sampling of the tumour failed to reveal any papillae with fibrovascular core or areas of necrosis. However, few glomeruloid structures, pseudopapillae and occasional psammoma bodies were noticed along with foci of microcalcification and collection of foam cells (Table/Fig 1) (c-g). By immunohistochemistry, the tumour was strongly positive for CK-7, vimentin, EMA and AMACAR but negative for S-100 and WT1 (Table/Fig 2) (a-c). Based on morphological findings and immunohistochemistry a final diagnosis of solid papillary renal cell carcinoma was rendered. The post-operative course was uneventful. Last follow-up, 18 months after excision, the patient was well and without any evidence of metastasis.
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Discussion |
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Papillary RCC is the second most common carcinoma arising from the renal tubular epithelium and comprises 10-15% of cases in surgical series (1). To be called as a papillary RCC, at least 75% of the tumour should be composed of papillary or tubulopapillary histology with fibrovascular cores (2). Several subtypes of papillary RCC had been described (1). In 1997, Renshaw AA et al., in their series of 6 cases defined the solid variant of papillary RCC as those RCCs that lack true papillae but contain the characteristic immunohistochemical and genetic features of papillary RCC (3). Although, first described in 1997, to best of our knowledge, only few cases have been described so far (4),(5),(6),(7).
Histopathological sections from papillary RCCs show papillary or tubulopapillary structures lined by small, cuboidal cells with basophilic cytoplasm or by larger cells with eosinophilic cytoplasm (1). Collections of foamy macrophages within the papillary stalks, iron deposition, and psammoma bodies are a frequent feature of these tumours. Although, papillary RCC was originally defined histologically, these tumours also have characteristic immunohistochemical features. Papillary RCC is typically immunoreactive for cytokeratin 7, cytokeratin 8/18, CD10, epithelial membrane antigen vimentin and a-Methylacyl co-enzyme A racemase (8). Papillary RCC often show foci of solid areas admixed with tubulopapillary areas. In this report, we describe a tumour with a solid and tubular growth pattern completely lacking true papillae or spindle cell areas. The tumour retained the immunohistochemical findings of papillary renal cell carcinoma and showed immunoreactivity for CK-7, vimentin, EMA and AMACAR but was negative for WT 1 and S100.
The main differential diagnosis of s-PRCC includes Metanephric Adenoma (MA) and Collecting Duct Carcinoma (CDC).
Although, MA and s-PRCC share some morphological features, some architectural and cytological characteristics may be useful in their distinction (7) (Table/Fig 3). MA cells are uniform, small, with high nuclear: cytoplasmic ratio, and show bland nuclei with delicate chromatin and absent or inconspicuous nucleoli. In contrast, the cells in s-PRCC are less uniform, with a variable nuclear: cytoplasmic ratio and occasional larger cells containing larger amounts of cytoplasm. The nuclei shows open or vesicular chromatin and nucleoli are present. Mitosis is very rare or absent in MA.
In particularly challenging cases, the use of IHC markers may be an important aid in reaching an accurate diagnosis. MA show strong positivity for WT1 and are negative for CK7, EMA, vimentin and AMACAR. The reverse holds true for solid papillary renal cell carcinoma. Histologically, CDC often has a mixed papillary and infiltrative tubular architecture. The infiltrative component is associated with marked stromal desmoplasia. Foci of dysplasia, or carcinoma in situ, can be found in the adjacent collecting ducts in some cases. The tumours are of high nuclear grade, corresponding to Fuhrman grade 3 or 4 (8). On immunohistochemistry, CDC is strongly positive for Ulex European agglutinin 1 lectin. CDC is also positive for Peanut Agglutinin (PNA), vimentin, lysozyme, distal tubular marker EMA, and high molecular weight cytokeratin, and negative for proximal tubular markers (RCC marker and CD10) (9).
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Conclusion |
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In this case of RCC, tumour cells were arranged in tubules and focal solid areas. The tumour lacked any true papillae. The tumour showed focal glomeruloid structures. The histopathological findings made it difficult to distinguish it from metanephric adenomas. The immunohistochemical findings showing positivity for CK7, EMA, Vimentin and AMACAR and negativity for WT1 helped to reach the diagnosis of solid papillary RCC. Despite the lack of true papillae, tumour is best classified as a solid variant of papillary RCC. This case is one of the few cases of s-PRCC reported in the literature.
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| 1. | Ulamec M, Skenderi F, Trpkov K, Kruslin B, Vranic S, Bulimbasic S, et al. Solid papillary renal cell carcinoma: clinicopathologic, morphologic, and immunohistochemical analysis of 10 cases and review of the literature. Ann Diagn Pathol. 2016;23:51-57. | 2. | Amin MB, Corless CL, Renshaw AA, Tickoo SK, Kubus J, Schultz DS. Papillary (chromophil) renal cell carcinoma: Histomorphologic characteristics and evaluation of conventional pathologic prognostic parameters in 62 cases. Am J Surg Pathol. 1997;21(6):621-35. | 3. | Renshaw AA, Zhang H, Corless CL, Fletcher JA, Pins MR. Solid variants of papillary (chromophil) renal cell carcinoma: clinicopathologic and genetic features. Am J Surg Pathol. 1997;21(10):1203-09. | 4. | Ngan KW, Ng KF, Chuang CK. Solid variant of papillary renal cell carcinoma. Chang Gung Med J. 2001; 24(9):582-86. | 5. | Argani P, Netto GJ, Parwani AV. Papillary renal cell carcinoma with low grade spindle cell foci: a mimic of mucinous tubular and spindle cell carcinoma. Am J Surg Pathol. 2008;32(9):1353-59. | 6. | Cantley R, Gattuso P, Cimbaluk D. Solid variant of papillary renal cell carcinoma with spindle cell and tubular components. Arch Pathol Lab Med. 2010;134:1210-14. | 7. | Padilha MM, Billis A, Allende D, Zhou M, Magi-Galluzzi M. Metanephric adenoma and solid variant of papillary renal cell carcinoma: common and distinctive features. Histopathology 2013;62:941-53. | 8. | Srigley JR, Eble JN. Collecting duct carcinoma of the kidney. Semin Diagn Pathol. 1998;15(1):54-67. | 9. | Truong LD, Shen SS. Immunohistochemical diagnosis of renal neoplasms. Arch Pathol Lab Med. 2011;135(1):92-109. [ Google Scholar]
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TABLES AND FIGURES | |
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