NAB2::STAT6 Rearranged Carcinoma of the Parotid Gland with Sebaceous Differentiation: A Case Report.

Purpose: The NAB2::STAT6 fusion is predominantly associated with solitary fibrous tumors (SFTs) and is utilized in diagnosing SFTs through nuclear STAT6 protein overexpression. Recent studies expanded the phenotypic spectrum of NAB2::STAT6 rearranged neoplasms, including adamantinoma-like and teratocarcinosarcoma-like phenotypes. We report a case of a NAB2::STAT6 rearranged epithelial tumor exhibiting sebaceous differentiation in the parotid gland.

Inflammatory Pseudotumor of the Ulnar Nerve Mimicking a Malignant Peripheral Nerve Sheath Tumor: A Radiologic Puzzle.

Inflammatory pseudotumor (IPT) of a peripheral nerve is a rare non-neoplastic tumefactive inflammatory condition, often mimicking malignancy. The etiology of this condition is still unknown. Clinically and radiologically, the lesion can mimic a malignant tumor.

Artificial intelligence in digital pathology of cutaneous lymphomas: A review of the current state and future perspectives.

Primary cutaneous lymphomas (CLs) represent a heterogeneous group of T-cell lymphomas and B-cell lymphomas that present in the skin without evidence of extracutaneous involvement at time of diagnosis. CLs are largely distinct from their systemic counterparts in clinical presentation, histopathology, and biological behavior and, therefore, require different therapeutic management. Additional diagnostic burden is added by the fact that several benign inflammatory dermatoses mimic CL subtypes, requiring clinicopathological correlation for definitive diagnosis.

Ambiguous melanocytic lesions: A retrospective cohort study of incidence and outcome of melanocytic tumor of uncertain malignant potential (MELTUMP) and superficial atypical melanocytic proliferation of uncertain significance (SAMPUS) in the Netherlands.

Background: Melanocytic tumor of uncertain malignant potential (MELTUMP) and superficial atypical melanocytic proliferation of uncertain significance (SAMPUS) are descriptive and provisional terms for melanocytic tumors with ambiguous histopathological features that are not easily classified as either benign or malignant.

Objective: To investigate the incidence and clinical outcome of MELTUMP and SAMPUS in the Netherlands.

Methods: In this retrospective cohort study, we reviewed all diagnoses of MELTUMP and SAMPUS from the Dutch Nationwide Pathology Databank from 1991 to October 1, 2021.

Validity of a two-antibody testing algorithm for mismatch repair deficiency testing in cancer; a systematic literature review and meta-analysis.

Reflex mismatch repair immunohistochemistry (MMR IHC) testing for MLH1, PMS2, MSH2 and MSH6 is used to screen for Lynch syndrome. Recently MMR-deficiency (MMRd) has been approved as a pan-cancer predictive biomarker for checkpoint inhibitor therapy, leading to a vast increase in the use of MMR IHC in clinical practice. We explored whether immunohistochemical staining with PMS2 and MSH6 can be used as a reliable substitute.

Intraosseous hibernoma of the appendicular skeleton.

Hibernomas are rare lipomatous tumors composed of brown adipocytes. The relative paucity of reported cases involving the bones accounts for the poor understanding of this entity, which is known to affect almost exclusively the axial skeleton. We present a case of intraosseous hibernoma of the humerus, which was found incidentally in a 52-year-old woman and initially misinterpreted as a cartilaginous tumor on magnetic resonance imaging (MRI).

Nonclinical evaluation of CNS-administered TPP1 enzyme replacement in canine CLN2 neuronal ceroid lipofuscinosis.

The CLN2 form of neuronal ceroid lipofuscinosis, a type of Batten disease, is a lysosomal storage disorder caused by a deficiency of the enzyme tripeptidyl peptidase-1 (TPP1). Patients exhibit progressive neurodegeneration and loss of motor, cognitive, and visual functions, leading to death by the early teenage years. TPP1-null Dachshunds recapitulate human CLN2 disease.