The reported diagnostic yield from bronchoscopies in patients with lung cancer varies greatly. The optimal combination of sampling techniques has not been finally established.

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.

A feature of myeloproliferative neoplasia is transforming to more aggressive and malignant myeloid neoplasia, including acute myeloid leukemia. Different pathogenesis mechanisms participate in transformation, including transformation of existing potential preleukemic clones, since JAK2-mutant myeloproliferative neoplasms often transform to JAK2 wild-type acute myeloid leukemia. Here, we present an 80 year old man with a JAK2-V617F mutant primary myelofibrosis. After 10 months the disease transform into a Philadelphia chromosome positive acute myeloid leukemia, detecting the cytogenetic aberration; t(9;22)(q34;q22) encoding the rare BCR-ABL1 fusion gene; e6a2. The patient had treatment response to tyrosine kinases, illustrating the potential benefits of such approach in treating these patients subset. The case illustrates the potential of leukemic transformation to Philadelphia chromosome positive myeloid malignancies from potential existing preleukemic clones, and the awareness of such an evolution among patients with myeloproliferative neoplasms. Tyrosine kinases have potential effect also in patients presenting without chronic myeloid leukemia and with rare BCR-ABL1 fusion transcripts, and should probably be a part of the treatment approach.

The polymer polyvinylpyrrolidone (PVP) is an excipient widely used in prescription drugs. Depending on the molecular weight (MW), parenterally administered PVP may accumulate in various tissues. Consequently, moderate and high MW PVP have only been used in oral preparations since the late 1970s. Surprisingly, starting in 2009, pathology departments in Norway received biopsies revealing PVP deposition, all from patients with a history of intravenous drug use. We identified 13 patients with PVP deposition and re-evaluated 31 biopsies and two autopsies. Common indications for biopsy were renal insufficiency, anemia, pathological fractures, and abdominal complaints. We observed PVP deposits in all biopsies (kidney, hematopoietic bone marrow, bone, gastrointestinal tract, lymph node, and skin) and all sampled tissue from the autopsies. Overall, the clinical findings could be related to PVP deposits in the biopsies. In the most seriously affected patients, PVP deposition caused severe organ dysfunction and contributed to the fatal outcomes of two patients. All patients except for one were prescribed opioid substitution drugs (OSDs), and most of the patients admitted to having injected such medications. Several OSDs contain PVP. One methadone formulation that was marketed in Norway from 2007 to 2014 contained large amounts of very high MW PVP, making it the most likely source of PVP deposition. Although the presumed source of PVP in these patients has now been withdrawn from the market, pathologists should be aware of PVP deposits when evaluating biopsies from this patient group.