Figures (4)  Tables (2)

    • Figure 1. 

      Photomicrograph showing tumor cells organized in nests with clear cytoplasm, well-defined cytoplasmic borders, little cytological atypia, and hyperchromatic nuclei (H&E, ×400).

    • Figure 2. 

      Photomicrograph showing foci of conventional adenocarcinoma (H&E, ×400).

    • Figure 3. 

      Photomicrograph showing tumor cells diffuse positivity for CK-7 by IHC at low power (×100) (a) and at high power (×400) (b). IHC, immunohistochemistry; CK-7, cytokeratin-7.

    • Figure 4. 

      Photomicrograph showing tumor cells positivity for AFP by IHC (×400). AFP, alpha-fetoprotein; IHC, immunohistochemistry.

    • Author Number of reported cases Age (years)/sex Cholelithiasis Histology Lymph node metastasis Outcome
      Maharaj et al. [5] 1 56/F yes CCG no AWD, on CT
      Zhang et al. [14] 1 80/M no CCG with hepatoid differentiation + FOCA yes 19 months disease-free
      Eken et al. [8] 1 56/F no CCG nd nd
      Sentani et al. [12] 1 78/F no AFP-producing CCG with neuroendocrine differentiation no 8 months disease-free
      Vaillo et al. [24] 1 72/F no CCG nd AWD, on CT
      Piana et al. [25] 1 66/F yes Combined CCG + small cell carcinoma + FOCA no 3 years DOD
      Bittinger et al. [15] 3 53–77/F yes (in 2 cases) CCG yes (in all cases) nd
      Vardaman Albores-Saavedra et al. [6] 7 56–68/F yes (in all cases) AFP-producing CCG and hepatoid differentiation in 1 case
      Others-CCG + FOCA + areas of mucinous carcinoma (in 2 cases)      		 yes (in 2 cases) 5 cases-DOD
      2 cases-AWD
      Present case 1 60/F yes AFP-producing CCG + FOCA no AWD, on CT
      CCG, clear-cell carcinoma of the gallbladder; FOCA, foci of conventional adenocarcinoma; ND, not determined; CT, chemotherapy; AWD, alive with disease; DOD, dead of disease; AFP, alpha-fetoprotein.

      Table 1. 

      Previously reported cases of CCG [5, 6, 8, 12, 14, 15, 24, 25]

    • Other clear cell tumors Age, years/sex Microscopy IHC
      Metastatic RCC [16–18] 39–84/M Solid, alveolar, and acinar pattern of cells with abundant clear cytoplasm and central or eccentric hyperchromatic nuclei. The characteristic network of small, thin-walled vasculature +ve for PAX-8
      PAX-2, CD-10, vimentin, and CA IX
      −ve for CK-7, CK-20, and CEA
      Clear-cell carcinoma of the ovary [15, 19] 50–70/F Solid, papillary, and tubulocystic pattern lined by clear or hobnail cells. Papillae are frequently hyalinized +ve for EMA, CK and CA-125
      −ve for CK-7, CK-20, and CEA
      Endometrial clearcell carcinoma [15, 20] 62–67/F Solid, papillary, tubular, and cystic architecture composed of polygonal cells with abundant clear or eosinophilic cytoplasm, and hobnail cells. Marked nuclear atypia and high mitotic activity +ve for 34βE12
      Leu-M1, vimentin, BCL-2, CEA, P-53, and CA-125
      ER, HER-2, and CK-7 are +/−. -ve for CK-20 and PR
      Clear-cell hepatocellular carcinoma [15, 21] Elderly/F Trabecular, acinar, or compact pattern of polygonal cells with clear, vacuolated or foamy cytoplasm. Central or eccentric nucleus, frequently dispersed among conventional neoplastic hepatocytes +ve for Hep par 1, arginase-1, and AFP
      −ve for CK-7, CK-19, EMA, CK-20, and CEA
      CCG, clear-cell carcinoma of the gallbladder; IHC, immunohistochemistry; RCC, clear-cell renal carcinoma; CEA, carcinoembryonic antigen; CK-7, cytokeratin-7; PAX-8, paired box gene 8.

      Table 2. 

      Differential diagnosis of CCG [15–21]