Eosinophilic solid and cystic renal cell carcinoma with aggressive behavior: Two case reports

BACKGROUND

Eosinophilic solid and cystic (ESC) renal cell carcinoma (RCC), a unique and emerging subtype of RCC, has an indolent nature; in some rare instances, it may exhibit metastatic potential. Current cases are inadequate to precisely predict the clinical outcome of ESC RCC and determine treatment choices.

CASE SUMMARY

Herein, we report two patients with ESC RCC. Patient 1 was a young woman with classical pathological characteristics. Patient 2 was a 52-year-old man with multifocal metastases, involving the pulmonary hilar and mediastinal lymph nodes, liver, brain, mesosternum, vertebra, rib, femur, and symphysis pubis. Awareness of ESC RCC, along with its characteristic architecture and immunophenotype, would contribute to making a definitive diagnosis, even on core biopsy samples.

CONCLUSION

The discovery of ESC RCC molecular signatures may provide new therapeutic strategies in the future.

Angiomyolipoma With Epithelial Cysts: A Rare but Distinct Variant of Angiomyolipoma

Renal angiomyolipomas, common benign tumors, can exhibit slow growth in sporadic cases or have aggressive tendencies when linked to genetic conditions like tuberous sclerosis. This case report focuses on the exceptionally rare angiomyolipoma with epithelial cysts (AMLEC) variant, particularly challenging to diagnose due to its scarcity. Describing a 41-year-old woman's case, initially suspected to be renal cell carcinoma during an infertility evaluation, subsequent partial nephrectomy revealed a tumor comprising smooth muscle, blood vessels, and fat, with cystic regions featuring cuboidal linings and a layer devoid of abnormal cell activity. Immunohistochemistry confirmed specific markers within different tumor components, highlighting the diagnostic complexities of AMLEC and emphasizing the crucial role of histopathological examinations in accurate characterizations.

Angiomyolipoma with epithelial cysts, an unexpected discovery in a gunshot abdomen: a single case report

Background

Angiomyolipoma with epithelial cysts is a rare variant of an angiomyolipoma that typically occurs sporadically. Patients with pre-existing kidney lesion or disease have significantly increased risk of morbidity and mortality associated with trauma. Abnormal and diseased kidneys are frequently injured by low or insignificant velocity impacts. The vulnerability of these kidneys is related to the type of pathology. However, cystic or hydronephrotic kidneys are more susceptible to trauma. Recent studies have shown an association of this rare entity with tuberous sclerosis complex. Despite the rarity of genetic association of Angiomyolipoma with epithelial cysts and tuberous sclerosis, the emerging findings raise the necessity of genetic testing of these lesions to confirm a remote possibility of tuberous sclerosis complex.

Case presentation

We report a case of a 38-year-old male patient who sustained a right renal injury as a result of a gunshot to the abdomen and underwent an emergency nephrectomy due to hemodynamic instability. A grossly looking shattered kidney was surgically removed. The morphology in conjunction with immunohistochemistry of the specimen favoured a diagnosis of Angiomyolipoma with epithelial cysts.

Conclusion

This is the first reported case of angiomyolipoma with epithelial cysts diagnosed on a nephrectomy specimen from renal trauma. We aim to highlight an approach to renal trauma on a kidney with pre-existing AMLEC as well as an approach to adult cystic renal neoplasms and to propose the importance of genetic testing for Tuberous Sclerosis.

Eosinophilic solid and cystic renal cell carcinoma: a single Indian tertiary center experience of three cases of a newly described entity

Background

Among adult malignant tumors, renal cell carcinoma accounts for 2–3% and has the worst prognosis among common urologic tumors. Recently, an eosinophilic, solid and cystic (ESC) renal cell carcinoma (RCC) histological subtype has been described and proposed as an entity separate than the 16 subtypes described in the 2016 WHO classification. The aim of the present study is to share our experience of three such cases of this newly described entity.

Methods

We retrospectively reviewed our cases of renal cell carcinoma and describe the presentation, diagnosis and management with follow-up details of ESC RCC.

Results

Our three patients presented at an advanced stage with flank pain or mass, and one patient had metastasis. All patients underwent radical nephrectomy, diagnosis proved by histopathological examination with immunohistochemistry (IHC), with abundant eosinophilic cytoplasm in all three cases. On IHC, CK 20 was positive in two cases and one patient with CK 20, CK 7 negative and PAX 8 positive.

Conclusions

ESC RCC is a newly described entity, with increasing incidence probably due to better diagnosis. Previously, 66 such cases are described, with female predominance, lower stage and indolent behavior. Only four cases with metastasis are described.

Key Renal Neoplasms With a Female Predominance

Renal neoplasms largely favor male patients; however, there is a growing list of tumors that are more frequently diagnosed in females. These tumors include metanephric adenoma, mixed epithelial and stromal tumor, juxtaglomerular cell tumor, mucinous tubular and spindle cell carcinoma, Xp11.2 (TFE3) translocation-associated renal cell carcinoma, and tuberous sclerosis complex (somatic or germline) associated renal neoplasms. The latter category is a heterogenous group with entities still being delineated. Eosinophilic solid and cystic renal cell carcinoma is the best-described entity, whereas, eosinophilic vacuolated tumor is a proposed entity, and the remaining tumors are currently grouped together under the umbrella of tuberous sclerosis complex/mammalian target of rapamycin-related renal neoplasms. The entities described in this review are often diagnostic considerations when evaluating renal mass tissue on biopsy or resection. For example, Xp11.2 translocation renal cell carcinoma is in the differential when a tumor has clear cell cytology and papillary architecture and occurs in a young or middle-aged patient. In contrast, tuberous sclerosis complex-related neoplasms often enter the differential for tumors with eosinophilic cytology. This review provides an overview of the clinical, gross, microscopic, immunohistochemical, genetic, and molecular alterations in key renal neoplasms occurring more commonly in females; differential diagnoses are also discussed regardless of sex predilection.

Glomus Tumor of the Kidney in a Child With Tuberous Sclerosis

Primary glomus tumors of the kidney are rare and have never been reported in children under 16 years of age. Tuberous sclerosis complex (TSC) is an extremely variable genetic condition that can affect virtually any organ in the body. Only a single case of glomus tumor associated with TSC was reported in 1964. In this article, we describe the clinical, radiologic, and pathological features of a primary renal glomus tumor in an 8-year-old girl with TSC. This tumor is large, has a deep location, and has infiltrative margins and numerous mitoses. However, there was no disease progression in a 16-month period of follow-up. To our knowledge, this is the second report of primary renal glomus tumor in childhood, the youngest one in the literature.