Crystal-storing histiocytosis (CSH) is an uncommon condition in which histiocytes accumulate a crystalline matter within their cytoplasm. Generally, those crystals are composed of either monoclonal or polyclonal immunoglobulin chains, which have a strong association with an underlying lymphoproliferative or plasma cell disorder (LP-PCD). Rarely, CSH has been reported as local or generalized manifestation of a variety of benign disorders. These cases are associated with crystals composed of nonimmunoglobulin substances. We are reporting an exceptional case of a local colonic CSH with Charcot–Leyden crystals. This patient underwent a screening colonoscopy that detected some polyps. The biopsy reported tubular adenomas, with a markedly dense, transmural inflammatory infiltrates, which were predominantly composed of eosinophils and crystal-storing histiocytes containing Charcot–Leyden crystals. The patient had a negative workup for LP-PCD and autoimmune conditions, including a normal skeletal survey and bone marrow aspirate/biopsy. The only positive laboratory workup was an elevated absolute eosinophil count and a positive IgG anti-
Crystal-storing histiocytosis (CSH) is a unique entity presenting as sheets of histiocytes with accumulation of crystalline matter within the cytoplasm. It can present as either a localized or generalized disease and has a variable outcome depending on the underlying CSH etiology [
A 55-year-old man with a history of hypertension, hyperlipidemia, gout, recurrent
Medium power H&E of the colonic mucosa demonstrating a diffuse expansion of the lamina propria by eosinophils (denoted by black bracket). There is displacement of the colonic crypts (black arrows). No other inflammatory cell types are seen.
High power H&E showing aggregates of histiocytes within the muscularis mucosa and superficial submucosa. The cytoplasm of the histiocytes contains eosinophilic Charcot–Leyden crystals which are present in the form of fine, granular, and needle-shaped deposits within the macrophage cytoplasm (black arrows).
Around 90% cases of crystal-storing histiocytosis (CSH) are associated with an underlying LP-PCD such as multiple myeloma (MM), lymphoplasmacytic lymphoma (LPL), and monoclonal gammopathy of undetermined significance (MGUS) [
Approximately 8.8% of CSH cases are seen in association with a variety of benign disorders. Conditions with hyperactivated immune system such as rheumatoid arthritis, Fanconi syndrome, Crohn’s disease, eosinophilic colitis, and mastocytosis; infections like
Nonimmunoglobulin CSH reported in literature.
Source | Sex/age | Patient history/underlying disease | Organ(s) involved by CSH | Type of crystal | Symptoms/indication for workup | Disease status at last follow-up |
---|---|---|---|---|---|---|
Sukpanichnant [ | M/32 y | Leprosy | SI and LN | Clofazimine crystals | Chronic abdominal pain | Died 2 months after diagnosis; had an acute onset of dyspnea |
Gebrail [ | M/23 y | Hereditary cystinosis | Cornea, conjunctiva, BM | Cystine crystals | Pancytopenia | Not described |
Pais [ | F/44 y | Leprosy | Intra-abdominal LN, omentum, and peritoneum | Clofazimine crystals | Mild abdominal pain | Complete remission |
Lewis [ | F/78 y | Eosinophilic colitis | Colon | Charcot–Leyden crystals | Chronic abdominal pain and diarrhea | Not described |
Singh [ | M/19 y | Leprosy | Duodenum and jejunum | Clofazimine crystals | Acute abdominal pain | Complete remission |
Szeto [ | F/68 y | Disseminated | Terminal ileum | Clofazimine crystals | Abdominal pain, diarrhea, weight loss, and hematochezia | Complete remission |
Present case | M/55 y | Strongyloidiasis | Proximal ascending colon | Charcot–Leyden crystals | Epigastric pain | — |
F, female; M, male; y, years; SI, small intestine; BM, bone marrow; LN, lymph nodes.
Besides the composition of the crystals, CSH can be classified as localized CSH (L-CSH), involving only one organ or site such as lung, pleura, stomach, kidney, bone marrow, thyroid, thymus, and parotid gland [
Charcot–Leyden crystals have hexagonal and bipyramidal forms [
Strongyloidiasis is a disease caused by a nematode
CSH has been reported as a first manifestation or a subclinical stage of underlying neoplasms such as thymic lymphoma, multiple myeloma, or lymphoreticular malignancy [
In conclusion, CSH is an uncommon phenomenon of aggregation of crystals within the histiocytic cytoplasm, which are usually made up of immunoglobulins. Nonimmunoglobulin CSH is extremely rare and is usually associated with benign conditions. We report here a Charcot–Leyden colonic-only CSH associated with
Manuel Beltran and Sharad Khurana are co-first authors.
The authors do not have any relevant conflicts of interest to report for this work.
Manuel Beltran and Sharad Khurana contributed equally to this work.