Anatomic pathology selected abstracts

Create PDF

Correspondence: Dr. Stuart J. Schnitt at sschnitt@bwh.harvard.edu

Gastric crystal-storing histiocytosis: a clue to hematolymphoid malignancies

Crystal-storing histiocytosis is an under-recognized entity that has a striking association with lymphoproliferative disorders. To study the typical morphologic features of gastric crystal-storing histiocytosis (CSH), the authors retrieved all lymphomas diagnosed using in-house gastric specimens at the Ohio State University between Jan. 1, 2008 and Jan. 1, 2017. This search yielded 66 specimens from 51 unique patients. All cases were reviewed, and CSH was identified in seven stomach biopsies from four patients (two men and two women; average age, 69 years; range, 56–82 years). The patients’ endoscopic findings were abnormal—diffuse nodularity and white discoloration (n = 1), patchy nodularity (n = 1), and malignant-appearing fundic mass with lymphadenopathy (n = 2). The typical gastric CSH lesion displays full-thickness expansion of the lamina propria by a lymphohistiocytic infiltrate that distorts the usual gastric glandular architecture. On high power, all cases were defined by the presence of macrophages with abundant eosinophilic cytoplasm containing nonrefractile, nonpolarizable fibrillary cytoplasmic inclusions. Three of the four patients had a kappa-restricted lymphoma; the one patient with a lambda-restricted lymphoma had the fewest macrophages. Follow-up data were available up to 228 weeks. All four patients had persistent/recurrent lymphoma, and two patients died of lymphoma-related complications. None of the CSH cases were prospectively recognized as CSH, and one case was initially misdiagnosed as a xanthoma. Because CSH can be so florid as to obscure the concomitant lymphoma, awareness is crucial for accurate diagnosis.

Arnold CA, Frankel WL, Guo L, et al. Crystal-storing histiocytosis in the stomach: A clue to subtle hematolymphoid malignancies. Am J Surg Pathol. 2018;42(10):1317–1324.

Correspondence: Dr. Christina A. Arnold at christina.arnold@osumc.edu

Landscape of immune microenvironment in hepatocellular carcinoma

Immune cells constitute an important element of tumor tissue. Accumulating evidence indicates their clinicopathological significance in predicting prognosis and therapeutic efficacy. Nonetheless, the combinations of immune cells forming the immune microenvironment and their association with histological findings remain largely unknown. Moreover, it is unclear which immune cells or immune microenvironments are the most prognostically significant. The authors conducted a study in which they comprehensively analyzed the immune microenvironment and its intratumor heterogeneity in 919 regions of 158 hepatocellular carcinomas (HCCs) and compared the results with corresponding histological and prognostic data. They classified the immune microenvironment of HCC into three distinct immunosubtypes: immune high, immune mid, and immune low. The immune-high subtype was characterized by increased B-/plasma-cell and T-cell infiltration, and the immune-high subtype and B-cell infiltration were identified as independent positive prognostic factors. Varying degrees of intratumor heterogeneity of the immune microenvironment were observed, some of which reflected the multistep nature of HCC carcinogenesis. However, the predominant pattern of immunosubtype and immune cell infiltration of each tumor was prognostically important. Of note, the immune-high subtype was associated with poorly differentiated HCC, cytokeratin 19+ (CK19+), Sal-like protein 4+ (SALL4+) high-grade HCC, and Hoshida’s S1/Boyault’s G2 subclasses. Patients with high-grade HCC of the predominant immune-high subtype had significantly better prognosis. These results provide a rationale for evaluating the immune microenvironment in addition to the usual histological and molecular classification of HCC.

Kurebayashi Y, Ojima H, Tsujikawa H, et al. Landscape of immune microenvironment in hepatocellular carcinoma and its additional impact on histological and molecular classification. Hepatology. 2018;68(3):1025–1041.

Correspondence: Dr. M. Sakamoto at msakamot@z5.keio.jp