1861Brigham and Women's Hospital and 1811Harvard Medical School, Boston, MA, USA.
6470Kaiser Foundation Hospital, 158530Southern California Permanente Medical Group, Baldwin Park, CA, USA.
Int J Surg Pathol. 2022 Apr;30(2):184-189. doi: 10.1177/10668969211026241. Epub 2021 Jun 28.
Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a rare and clinically aggressive RCC subtype that is commonly associated with the hereditary leiomyomatosis and renal cell carcinoma syndrome. The diagnostic hallmark of FH-deficient RCC is a high-grade microscopic appearance with prominent inclusion-like eosinophilic nucleoli and perinucleolar halos. Herein we report a case of an FH-deficient RCC in a 30-year-old female that exhibited low-grade nuclei and abundant eosinophilic cytoplasm, reminiscent of the clinically more indolent succinate dehydrogenase-deficient RCC subtype and the newly described eintity, eosinophilic, solid and cystic RCC. This case illustrates that FH-deficient RCC can have a wide spectrum of microscopic appearances, including low-grade eosinophilic RCC. In addition, it highlights that a low threshold to perform the immunohistochemical stains for FH and S-(2-succino) cysteine is warranted in RCC cases with unusual and even low-grade eosinophilic morphology.
琥珀酸脱氢酶（FH）缺陷型肾细胞癌（RCC）是一种罕见且临床侵袭性较强的 RCC 亚型，通常与遗传性平滑肌瘤病和肾细胞癌综合征相关。FH 缺陷型 RCC 的诊断标志是具有高级别微观外观，突出的包涵体样嗜酸性核仁以及核周晕。在此，我们报告了一例 30 岁女性的 FH 缺陷型 RCC，其表现为低级别核，富含嗜酸性细胞质，类似于临床上惰性更强的琥珀酸脱氢酶缺陷型 RCC 亚型和新描述的实体，嗜酸性、实性和囊性 RCC。该病例说明 FH 缺陷型 RCC 可能具有广泛的微观表现，包括低级别嗜酸性 RCC。此外，它强调在具有不寻常甚至低级别嗜酸性形态的 RCC 病例中，有必要进行 FH 和 S-（2-琥珀酸）半胱氨酸的免疫组织化学染色，以降低门槛。
