Updates in pathobiological aspects of anaplastic large cell lymphoma

ALK + anaplastic large cell lymphoma involving the bladder: case report and review of the literature

We reported a case of anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALK + ALCL) involving the bladder. The patient was a 27-year-old female, whose main clinical symptoms included fever, painless lymphadenopathy, and hematuria. Imaging studies suggested a bladder mass. The bladder mass was maximally resected through transurethral bladder tumor resection. The pathology report indicated a malignant tumor of the bladder. Based on immunohistochemical and gene rearrangement results, the diagnosis was confirmed as ALK + ALCL. After undergoing five cycles of treatment with the BV + CHP chemotherapy regimen, the patient's condition is currently stable, and no tumor recurrence was observed upon re-examination. ALK + ALCL involving the bladder is very rare, and early diagnosis is challenging. By reviewing the diagnostic and treatment process of this patient, and in conjunction with a review of modern literature on the disease's incidence characteristics, treatment protocols, and prognosis, this aims to provide a reference for clinicians in diagnosing and treating this condition, thereby reducing delays.

Establishment and characterization of TK-ALCL1: a novel NPM-ALK-positive anaplastic large-cell lymphoma cell line

TK-ALCL1, a novel anaplastic lymphoma kinase (ALK)-positive anaplastic large-cell lymphoma (ALK+ ALCL) cell line, was established from the primary tumor site of a 59-year-old Japanese male patient. The immune profile of TK-ALCL1 corresponds to that seen typically in primary ALCL cells, i.e., positive for ALK, CD30, EMA, and CD4, but negative for CD2, CD3, CD5, CD8a, and EBV-related antigens. The rearrangement of the T cell receptor-gamma locus shows that TK-ALCL1 is clonally derived from T-lineage lymphoid cells. FISH and RT-PCR analysis revealed that TK-ALCL1 has the nucleophosmin (NPM)-ALK fusion transcript, which is typical for ALK+ ALCL cell lines. When TK-ALCL1 was subcutaneously inoculated into 6-week-old BALB/c Rag2-/-/Jak3-/- (BRJ) mice, it formed tumor masses within 4-6 weeks. Morphological, immunohistochemical, and molecular genetic investigations confirmed that the xenograft and the original ALCL tumor were identical. The ALK inhibitors Alectinib and Lorlatinib suppressed proliferation in a dose-dependent manner. Thus, TK-ALCL1 provides a useful in vitro and in vivo model for investigation of the biology of ALK+ ALCL and of novel therapeutic approaches targeting ALK.