Elsevier

Human Pathology

Volume 75, May 2018, Pages 132-136
Human Pathology

Case study
Unclassified hemangioma-like renal cell carcinoma: a potential diagnostic pitfall

https://doi.org/10.1016/j.humpath.2017.09.015Get rights and content

Highlights

  • Rarely, clear cell renal cell carcinoma can mimic hemangioma.

  • We report a tumor with non–clear cell appearance and unusual immunohistochemistry.

  • More study is needed to determine whether this represents a distinct tumor type.

  • Renal cell carcinoma should be excluded carefully before diagnosing renal hemangioma.

Summary

Recently, rare renal cell carcinomas (RCCs) have been reported to closely mimic hemangioma; however, these have been largely recognizable as clear cell RCC. Conversely, true hemangiomas of the kidney are also increasingly recognized. We report a 62-year-old woman who underwent partial nephrectomy for a hemangioma-like RCC without appreciable clear cell morphology. Immunohistochemistry revealed luminal structures that stained positively for cytokeratin, cytokeratin 7, carbonic anhydrase IX, PAX8, and high-molecular-weight keratin, admixed with a CD34-positive, CD31-positive, and ERG-positive complex network of vessels. Staining was minimal for α-methyl-acyl-coA-racemase and EMA, and absent for GATA3, HMB45, melan-A, and cathepsin K. Fluorescence in situ hybridization revealed no TFE3 or TFEB rearrangement, 3p deletion, or trisomy 7 or 17. This case adds to the spectrum of hemangioma-like RCC with differing morphology and immunophenotype. Further study will determine whether this represents a distinct entity or an unusual pattern of degenerative changes in an existing entity.

Introduction

Clear cell renal cell carcinoma with hemangioma-like degenerative changes can present a diagnostic dilemma [1]. Despite the kidney being a highly vascular organ, primary vascular tumors of this organ are actually rare [2], although recently the novel hemangioma subtype anastomosing hemangioma has been recognized to have more frequent occurrence in the kidney and genitourinary tract, among other sites [3], [4]. In general, predominant sinusoidal-like vascularity in a renal mass would have a differential diagnosis that includes hemangioma (especially anastomosing hemangioma), hemangioma-like degenerative changes in renal cell carcinoma (usually clear cell type), or spontaneous regression of renal cell carcinoma. There are a few reports of clear cell renal cell carcinoma mimicking a hemangioma [1], [5]; however, to our knowledge, non–clear cell hemangioma-like renal cell carcinoma has not been previously reported. In this article, we report a case of unclassified hemangioma-like renal cell carcinoma presenting in a 62-year-old woman.

Section snippets

Case report

A 62-year-old woman presented to the urology clinic with an incidentally detected asymptomatic left renal mass. The renal mass was under active monitoring for a 2-cm renal cyst, which progressed over 8 years into a solid mass. Computed tomography revealed a thick, enhancing capsule with a solid, enhancing central region suggestive of renal cell carcinoma. An elective partial nephrectomy was performed.

Methods

This study was approved by the Henry Ford Health System Institutional Review Board.

Results

At gross examination, the partial nephrectomy specimen contained a 2.6 × 2.5 × 2.5–cm well-circumscribed, encapsulated tan-brown hemorrhagic mass (Fig. 1). Microscopically, the morphological appearance was unusual with hemangioma-like features, extensive vascular component, fibrin accumulation, and hemorrhage. The areas with morphology suggestive of a renal epithelial component exhibited a tubulocystic appearance with flattened eosinophilic cells showing International Society of Urological

Discussion

Rich vascularity and an extensive capillary network separating nests of neoplastic cells are commonly used as diagnostic clues for a diagnosis of clear cell renal cell carcinoma, and it has been noted recently that some cases may mimic hemangioma when the epithelial component is inconspicuous and the residual vascular network predominates [1], [5], possibly resulting from degenerative changes. Conversely, hemangiomas can also occur in the kidney less frequently, potentially mimicking clear cell

Summary

In this report, we describe an unusual neoplasm, which we term unclassified hemangioma-like renal cell carcinoma, occurring in a 62-year-old woman, in which renal cell carcinoma harbored extensive arborizing vessels mimicking hemangioma. Immunohistochemical staining highlighted the epithelial component of tumor but with an abnormal combination of positive markers, including cytokeratin 7, high-molecular-weight cytokeratin, and carbonic anhydrase IX, with minimal labeling for AMACR and negative

References (16)

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Cited by (3)

  • The expanding role of renal mass biopsy

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    Other soft tissue type tumors in the kidney are diverse and can include solitary fibrous tumor, among a broad spectrum of entities.77 Several renal cell carcinomas have been recently recognized to mimic hemangioma, with a prominent vascular proliferation and subtle epithelial component.79–82 In these tumors, epithelial cells are often small and may resemble inflammatory cells or capillaries among the blood vessels and stroma (Figure 10).

  • Renal cell carcinomas with a mesenchymal stromal component: what do we know so far?

    2019, Pathology
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    It is relatively common for clear cell renal cell carcinoma tumours to include areas of fibrosis or scarring. Usually, this poses no diagnostic challenge; however, rare cases have been described in which the extent of scar or regressive change is so extensive that the epithelial component of the tumour is almost obscured, mimicking haemangioma (Fig. 6).77–79 For the most part, such tumours have straightforward features of clear cell renal cell carcinoma partially within the neoplasm, facilitating the diagnosis.

Disclosures: none.

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