Nonimmunoglobulin Crystal-Storing Histiocytosis (CSH)‎: Case Report and Literature Review

Abstract EN

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-Strongyloides antibody.

Giving those findings, this parasitic infection is the most likely etiology of the CSH in our patient.

Although there was an initial negative evaluation for LP-PCD, close monitoring of patients with either immunoglobulin or nonimmunoglobulin CSH is recommended.