Lymphoma diagnosis at an academic centre: rate of revision and impact on patient care.

Few studies have examined the value of a mandatory second review of outside pathology material for haematological malignancies. Therefore, we compared diagnoses on biopsies referred to an academic medical centre to determine the rate and therapeutic impact of revised diagnoses resulting from a second review. We reviewed 1010 cases referred for lymphoma during 2009-2010. For each case, referral diagnosis and second review diagnosis were compared. Revised diagnoses were grouped into major and minor discrepancies and all major discrepancies were reviewed by a haematologist to determine the effect the diagnostic change would have on therapy. There was no change in diagnosis in 861 (85·2%) cases. In 149 (14·8%) cases, second review resulted in major diagnostic change, of which 131 (12·9%) would have resulted in a therapeutic change. The highest rates of revision were for follicular, high-grade B-cell, and T-cell lymphomas. We found higher rates of major discrepancy in diagnoses from non-academic centres (15·8%) compared to academic centres (8·5%; P = 0·022), and in excisional biopsies (17·9%) compared to smaller biopsies (9·6%; P = 0·0003). Mandatory review of outside pathology material prior to treatment of patients for lymphoma will identify a significant number of misclassified cases with a major change in therapy.

Extramedullary hematopoiesis in a sentinel lymph node as an early sign of chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic malignancy with features of both a myeloproliferative neoplasm and a myelodysplastic syndrome. Even though extramedullary leukemic infiltration is common in CMML patients, lymph node involvement has rarely been reported in the literature. We present an unusual case of a 72-year-old female who was found to have extramedullary hematopoiesis (EMH) in a sentinel lymph node that was excised during mastectomy for lobular breast carcinoma. One year later bone marrow biopsy was performed due to persistent anemia, thrombocytopenia, and monocytosis and the patient was diagnosed with CMML. Our case illustrates the importance of recognizing EMH in a lymph node during routine histological examination, especially in adults. Proliferation of bone marrow elements in a lymph node, in a patient with no known hematologic disorder, should trigger immediate bone marrow evaluation, as this could be the first clue in diagnosing underlying bone marrow disorder.

Genomic imbalances in benign metastasizing leiomyoma: characterization by conventional karyotypic, fluorescence in situ hybridization, and whole genome SNP array analysis.

Benign metastasizing leiomyoma, a rare condition of controversial origin, is characterized by the occurrence of extrauterine smooth muscle tumors primarily affecting the lungs of women with a history of uterine leiomyomas. Numerous genetic studies of uterine leiomyoma with rearrangements of the HMGA2 and HMGA1 loci defined in prominent subgroups have been conducted. In contrast, cytogenetic and molecular descriptions of benign metastasizing leiomyoma are few, and, in particular, this entity has not been previously subjected to single nucleotide polymorphism (SNP) array analysis. In this study, conventional karyotypic, and/or molecular cytogenetic, and SNP array characterization of a pleuropulmonary benign mestasizing leiomyoma and a synchronous deep soft tissue leiomyoma of the thigh, which arose in a 56-year-old female with a remote history of uterine leiomyomata, revealed rearrangement of the HMGA1 (6p21) locus and nearly identical genomic profiles, including loss of chromosome 7 material in both lesions. These findings suggest that both the deep soft tissue and pleuropulmonary lesions were derived from the same abnormal clone and are genetically related to uterine leiomyomata.

The small round blue cell tumors of the sinonasal area.

The diagnostic classification of small round blue cell tumors of the sinonasal area to include diverse malignancies of epithelial, hematolymphoid, neuroectodermal, and mesenchymal origin is challenging to the surgical pathologist using conventional histopathologic approaches because the cytomorphologic features are often overlapping or indistinctive. Rare or occasional clinical presentations in atypical age groups or unusual locations, as well as small biopsy samples may further complicate the differential diagnosis. Immunohistochemistry represents an extensively investigated ancillary technique that may aid in the provision of a definitive diagnosis. In recent years, certain small round blue cell tumors have been shown by cytogenetic analysis to have specific and primary chromosomal alterations, providing clinicians with a valuable tool to enhance their diagnostic armamentarium. The addition of molecular cytogenetic [fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH)] and molecular pathologic [polymerase chain reaction (PCR) and reverse transcriptase (RT)-PCR] approaches has further enhanced the sensitivity and accuracy of detecting these genetic alterations including assessment in formalin-fixed, paraffin-embedded tissues. Establishing an accurate diagnosis of a small round blue cell tumor of the sinonasal tract frequently requires adjunctive studies including immunohistochemical and molecular analyses.