Hypercalcemia, Renal Failure, and Skull Lytic Lesions: Follicular Lymphoma Masquerading as Multiple Myeloma.

The findings of hypercalcemia, skull lytic lesions, and renal failure are usually characteristic for multiple myeloma. We herein describe an interesting case of B-cell follicular lymphoma that presented with many features mimicking multiple myeloma.

Unique occurrence of mucosa-associated lymphoid tissue lymphoma disseminated to peripheral nerves.

Lymphomatous spread to peripheral nerves is a rare but long recognized complication, most commonly involving aggressive B-cell lymphomas. A 67-year-old woman with a history of a low-grade, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, which was in remission, presented with a left-sided forearm mass and numbness over the dorsolateral aspect of the thumb. Magnetic resonance imaging revealed a mass associated with the superficial radial sensory nerve in the distal forearm, which demonstrated fluorodeoxyglucose avidity on positron emission tomography. An ultrasound-guided needle biopsy was performed yielding a diagnosis of low-grade lymphoma, consistent with extranodal marginal zone lymphoma. Subsequently, she was found to have bilateral sciatic nerve involvement. This case describes the first known reported spread of MALT lymphoma to peripheral nerves in the limbs.

Laboratory persistence and clinical progression of small monoclonal abnormalities.

Monoclonal gammopathy of undetermined significance (MGUS) that presents with no quantifiable M spike on immunofixation electrophoresis (IFE) can be termed IFE MGUS. We retrospectively identified patients with IFE MGUS who were monitored with at least 1 subsequent assessment that included an IFE, and evaluated the persistence of the monoclonal protein and the progression of disease. Although the monoclonal proteins persisted in the majority of patients, 16% did not experience this persistence, and had no documented immunomodulatory therapy. After a median follow-up of 3.9 years, the disease clinically progressed in 14 patients (3.2%). Eight of these 14 patients with clinical progression had an immunoglobulin (Ig) A IFE M protein and 6 had an IgG M protein. This study demonstrates that in some patients with IFE MGUS, the M proteins are transient and that IgA IFE MGUS is more likely to persist and progress to myeloma.

Correlation of thyroid nodule fine-needle aspiration cytology with corresponding histology at Mayo Clinic, 2001-2007: an institutional experience of 1,945 cases.

Following the National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference, the thyroid fine-needle aspiration biopsy (FNAB) practice at Mayo Clinic, Rochester, Minnesota, conducted retrospective analyses correlating cytologic and histologic evaluations of thyroid nodules. Cytologic and histologic reports were retrieved for patients with thyroid nodules who underwent thyroid FNAB between January 2001 and December 2007, with subsequent surgical thyroid resection. Cases were classified by major cytologic and histologic diagnosis and specific diagnostic subcategories. Of 1,945 FNAB cytologic results, 180 (9.3%) were nondiagnostic; 512 (26.3%) were negative for malignancy; 27 (1.4%) were atypical; 729 (37.5%) were suspicious for malignancy; and 497 (25.6%) were positive for malignancy. Histology was benign in 1,179 (60.6%) and malignant in 766 (39.4%). For thyroid malignancy as the disease outcome, at cytologic thresholds of atypical, suspicious, and positive, overall sensitivity of thyroid FNAB was 94.5%, 94.1%, and 65.0%, respectively, and specificity was 46.0%, 48.3%, and 98.5%, respectively. Positive predictive value for all malignancies was 97.0%, and negative predictive value was 92.0%. When separated by specific malignant outcomes, diagnoses of papillary carcinoma, medullary carcinoma, and lymphoma had specificity of suspicious FNAB diagnoses ranging from 90.5% to 99.6%; positive predictive value ranged from 87.5% to 91.4%. For follicular or Hürthle carcinoma, suspicious FNAB diagnoses had a specificity of 52.5% and a positive predictive value of 5.9%. Sensitivity of indeterminate FNAB diagnoses ranged from 72.7% to 95.3%. For follicular or Hürthle pattern malignancies, indeterminate cytologic diagnoses should be interpreted with caution by the clinician considering surgical management. Diagn. Cytopathol. 2012;40:E27-E32. © 2010 Wiley Periodicals, Inc.

Small Round Cell Tumors of Bone.

Diagnosing small round cell tumors (SCRTs) can be a difficult task for pathologists due to overlapping clinicopathologic features. This review highlights the clinical, radiographic, histologic, immunohistochemical, and genetic features of the most common SRCTs involving bone with an emphasis on differential diagnosis. SRCTs are a heterogeneous group of neoplasms characterized by poorly differentiated cells with small, blue, round nuclei and scant cytoplasm. They can occur as primary tumors in bone or soft tissue.