Isolated gastric crystal-storing histiocytosis: a rare marker of occult lymphoproliferative disorders

Crystal-Storing Histiocytosis: The Iceberg of More Serious Conditions

Crystal-storing histiocytosis is a rare condition that is histologically characterized by intracellular cytoplasmic crystalline inclusions. It usually presents monoclonal immunoglobulins that deposit within histiocytes, which accumulate and affect different organs of the human body and are commonly associated with lymphoproliferative conditions, especially those with plasmacytic differentiation. The prognosis of this condition is variable and related to the underlying clinical disease. In this review article, we aim to describe and discuss the clinical and pathological characteristics of crystal-storing histiocytosis based on the available literature and to provide a thorough differential diagnosis.

Crystal-storing histiocytosis in the stomach: A case report and review of the literature

Crystal-storing histiocytosis (CSH) is a rare disorder characterized by the accumulation of non-neoplastic histiocytes that contain intracytoplasmic crystallized immunoglobulins. Although CSH can occur in various organs, gastric CSH is very rare. Therefore, diagnosing gastric CSH remains a challenge. Here, we present the case of a 69-year-old man with localized gastric CSH who presented with positive fecal occult blood for 2 days. Gastroscopy showed that there was a piece of irregular whitish focus in the big bend of the gastric antrum, which was soft and elastic. Histologically, the biopsied gastric mucosa showed chronic inflammation, mild activity with erosion, and numerous eosinophilic mononuclear cells containing fibrillary crystalloid inclusions in the lamina propria. Immunohistochemically, these crystal-containing cells were positive for CD68/PGM1 and Igk, which revealed that the cells were histiocytes harboring kappa light chain-restricted immunoglobulin crystals. Electron microscopic examination showed numerous high-electron-density particles in the cytoplasm of cells, with crystal structures of different sizes and shapes. This case highlights how immunohistochemistry can help with differential diagnosis and classification.

Lambda-Restricted Crystal-Storing Histiocytosis of Stomach: A Case Report and Review of Literature

Crystal-storing histiocytosis (CSH) is a rare tissue phenomenon that is usually associated with lympho-proliferative diseases. The disease is characterized by prominent collections of macrophages with abundant eosinophilic cytoplasm and fibrillary cytoplasmic inclusions. The inclusions appear as linear crystals within the macrophages which are usually kappa restricted. The disease usually involves lungs, lymph nodes, bone marrow, thymus and spleen with rare involvement of the gastrointestinal tract. We report a rare case of lambda-restricted CSH of the stomach. The diagnosis of CSH triggered further hematological evaluation. The patient was later diagnosed to have diffuse large B-cell lymphoma involving lymph nodes and bone marrow. He received chemotherapy for the same and is on regular follow up. The index case highlights the need to identify CSH of stomach prompting evaluation for hematological malignancies and to increase its awareness among clinicians and pathologists.

Immunoglobulin-Storing Histiocytosis: A Case Based Systemic Review

Crystal-storing histiocytosis (CSH) is a rare event in disorders associated with monoclonal gammopathy and is mostly associated with the accumulation of immunoglobulins (Igs) in the cytoplasm of histiocytes. In this article, we present a case of a 75-year-old female with IgG kappa monoclonal gammopathy of undetermined significance (MGUS) and signs of a non-crystallized version of immunoglobulin-storing histiocytosis (IgSH) in a vertebra corpus. Furthermore, we performed a literature review based on all cases of storing histiocytosis identified by literature search between 1987 and 2020 and identified 140 cases in total. The median age at diagnosis was 60 years (range 18–91), with an equal sex distribution (51% men). The majority of the patients had an underlying neoplastic B-cell disorder, most often multiple myeloma (MM), MGUS, or lymphoplasmacytic lymphoma (LPL). The main affected organ systems or tissue sites were bone (n = 52), followed by head and neck (n = 31), kidney (n = 23), lung (n = 20), and gastrointestinal (GI)-tract (n = 18). IgG was the main immunoglobulin class involved, and most cases were associated with kappa light chain expression. We conclude that IgSH is a rare disease entity but should be considered with unusual findings in several organ systems associated with monoclonal gammopathy, especially with kappa light chain expression.

Gastric crystal-storing histiocytosis with concomitant mucosa-associated lymphoid tissue lymphoma

Crystal-storing histiocytosis (CSH) is a rare entity that is characterized by intrahistiocytic accumulation of crystallized immunoglobulins. CSH is not a malignant process per se, but the majority of CSH cases are associated with underlying lymphoproliferative disorder. Although CSH can occur in a variety of organs, gastric CSH is very rare. We present a localized gastric CSH with concomitant mucosaassociated lymphoid tissue (MALT) lymphoma, manifesting as an ulcer bleeding in a 56-year-old man. Histologically, the biopsied gastric mucosa demonstrated expansion of the lamina propria by prominent collections of large eosinophilic mononuclear cells containing fibrillary crystalloid inclusions. Immunohistochemical studies revealed that the crystal-storing cells were histiocytes harboring kappa light chain-restricted immunoglobulin crystals. Within the lesion, atypical centrocyte-like cells forming lymphoepithelial lesions were seen, consistent with MALT lymphoma. Since this entity is rare and unfamiliar, difficulties in diagnosis may arise. Particularly, in this case, the lymphomatous area was obscured by florid CSH, making the diagnosis more challenging.

Rare Gastric Lesions Associated with Helicobacter pylori Infection: A Histopathological Review

Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. However, some rare gastric lesions exhibiting distinctive histological features may also be associated with H. pylori infection, including lymphocytic gastritis, granulomatous gastritis, Russell body gastritis, or crystal-storing histiocytosis. Although diverse factors can contribute to their development, there is convincing evidence that H. pylori infection may play a pathogenic role. These findings are mainly based on studies in patients with these lesions who exhibited clinical and histological improvements after H. pylori eradication therapy. Thus, H. pylori eradication therapy might be indicated in patients with no other underlying disease, particularly in countries with a high prevalence of H. pylori infection. This review describes the characteristic histological features of these rare lesions and evaluates the evidence regarding a causative role for H. pylori infection in their pathogenesis.