Rhabdomyolysis: Revisited

Rhabdomyolysis (RML) is a pathological entity characterized by symptoms of myalgia, weakness and dark urine (which is often not present) resulting in respiratory failure and altered mental status. Laboratory testing for myoglobinuria is pathognomonic but so often not present during the time of testing that serum creatine kinase should always be sent when the diagnosis is suspected. Kidney injury from RML progresses through multiform pathways resulting in acute tubular necrosis. Early treatment (ideally<6 hoursfrom onset) is needed with volume expansion of all non-overloaded patients along with avoidance of nephrotoxins. There is insufficient data to recommend any specific fluid. The mortality rate ranges from 10% to up to 50% with severe AKI, so high index of suspicion and screening should be in care plan of seriously ill patients at risk for RML.

Minimal adenocarcinoma in prostate needle biopsy tissue

One of the major diagnostic challenges in prostate needle biopsy interpretation is definitive establishment of a malignant diagnosis based on a minimal or limited amount of carcinoma in needle biopsy tissue. Major and minor diagnostic criteria should be used for interpretation of small foci of carcinoma. The constellation of findings and a combination of the major and minor diagnostic criteria permit a definitive diagnosis of focal adenocarcinoma. The differential diagnosis of minimal prostatic adenocarcinoma in needle biopsy tissue is broad and includes many benign lesions. The benign entities most likelty to be misdiagnosed as minimal prostatic adenocarcinoma are atypical adenomatous hyperplasia (adenosis) and atrophy. High-grade prostatic intraepithelial neoplasia and a descriptive diagnosis of focal glandular atypia or atypical small acinar proliferation also should be considered before diagnosing minimal adenocarcinoma. The most valuable adjunctive study for the diagnosis of minimal adenocarcinoma is immunohistochemistry using antibody 34 beta E12, reactive against basal cell-specific high-molecular-weight cytokeratins. Most cases can be diagnosed based on H&E-stained sections without this immunostain. Most minimal carcinomas in prostate needle biopsy tissue are of intermediate histologic grade, and most are indicative of pathologically significant carcinoma in the whole prostate gland.

Visual estimate of the percentage of carcinoma is an independent predictor of prostate carcinoma recurrence after radical prostatectomy

BACKGROUND

The importance of tumor size measurements as predictors of disease recurrence after radical prostatectomy in patients with prostate carcinoma remains somewhat controversial, and many pathologists do not report these measurements routinely. The authors studied the correlation between the visual estimate of the percentage of carcinoma in prostatic tissue from radical prostatectomy specimens and prostate carcinoma recurrence rates in a series of 595 patients who underwent radical prostatectomy.

METHODS

A total of 595 men with clinically localized prostate carcinoma were treated by the same surgeon (W.J.C.) from 1993 through 1997. The percentage of carcinoma in radical prostatectomy specimens from these patients was assessed microscopically through visual estimate. The authors used Kaplan-Meier product limit estimates, log-rank statistics, and the Cox proportional hazards model to evaluate the percentage of carcinoma in the pathologic specimens as predictors of recurrence free survival.

RESULTS

Of the 595 patients, 46 (8%) had evidence of tumor recurrence. The mean percentage of carcinoma in the prostatectomy specimen was 11.3% in the group of patients who did not have disease recurrence and 23.8% in the group of patients who did experience disease recurrence. The percentage of carcinoma, preoperative prostate specific antigen levels, tumor differentiation (histologic Gleason grade), and pathologic stage all were significant predictors of disease recurrence according to the Kaplan-Meier method (all log-rank P values < 0.0001). Using the Cox proportional hazards model, controlling for all of these variables, only pathologic tumor stage, Gleason score, and percentage of carcinoma proved to be independent predictors of disease recurrence. In the final model, which included pathologic stage, Gleason score, and percentage of carcinoma, for each 5% increase in the percentage of carcinoma in the surgical specimen, there was an 11% incremental increase in the chance of tumor recurrence.

CONCLUSIONS

The visual estimate of the percentage of carcinoma in prostatic tissue specimens from patients who undergo radical prostatectomy is a practical, simple, and inexpensive method that provides important prognostic information after radical prostatectomy.

Transformation of monocytoid B-cell lymphoma to large cell lymphoma associated with crystal-storing histiocytes

We report a case of crystal-storing histiocytosis associated with large cell lymphoma in a patient with a history of monocytoid B-cell lymphoma 10 years previously. The cervical lymph node biopsy showed a diffuse proliferation of large lymphocytes with vesicular nuclear chromatin and distinct nucleoli. These lymphocytes were associated with numerous immunoglobulin lambda light-chain crystal-storing histiocytes, which morphologically resembled rhabdomyoblasts. Occasional lymphoid cells also showed large immunoglobulin crystals. This case establishes the association of crystal-storing histiocytes with lymphomas of mucosa-associated lymphoid tissue and emphasizes the need for immunophenotyping to distinguish these unusual cases from other tumors, particularly adult rhabdomyomas.

Minimal carcinoma in prostate needle biopsy specimens: diagnostic features and radical prostatectomy follow-up

Prostate cancer screening and early detection efforts have resulted in the identification of smaller volume carcinomas of the prostate. We evaluated the diagnostic features of minimal (< 1 mm) carcinoma in sextant needle biopsy specimens of the prostate and in follow-up analyzed the features of the corresponding carcinomas in the whole gland. We reviewed specimens from 50 consecutive patients who had minimal carcinoma in needle biopsy tissue and who had undergone radical prostatectomy. Histologic grade, tumor size, pathologic stage, and margin status of the 50 carcinomas in the whole gland in which the carcinoma size was minimal in the sextant needle biopsy specimen were compared with those of 50 carcinomas in the whole gland in which carcinoma size was greater than 1 mm in the needle biopsy specimen. The most common morphologic features of these minimal carcinomas were nucleomegaly (96%), infiltrative growth pattern (88%), intraluminal secretions (78%), prominent nucleoli (64%), associated high-grade prostatic intraepithelial neoplasia (40%), amphophilic cytoplasm (36%), hyperchromatic nuclei (30%), and intraluminal crystalloids (22%). Perineural invasion (2%), collagenous micronodules (2%) and mitotic figures (2%) were uncommon. The mean tumor volume in the whole gland of carcinomas corresponding to minimal carcinoma in a needle biopsy specimen was significantly smaller (P=.029) at 1.1 mL than it was in carcinomas with tumor greater than 1 mm in the needle biopsy specimen at 1.6 mL, but other pathologic features of carcinoma in the whole gland were not significantly different. In conclusion, a constellation of morphologic attributes is important for establishment of a diagnosis of minimal carcinoma of the prostate in needle biopsy specimen. Most (82%) of the corresponding prostate cancers in the whole gland were pathologically significant.

Analysis of graft-versus-host disease (GVHD) and graft rejection using MHC class I-deficient mice

GVHD is a major complication in allogeneic bone marrow transplantation (BMT). MHC class I mismatching increases GVHD, but in MHC-matched BMT minor histocompatibility antigens (mH) presented by MHC class I result in significant GVHD. To examine the modification of GVHD in the absence of cell surface MHC class I molecules, beta2-microglobulin-deficient mice (beta2m(-/-)) were used as allogeneic BMT recipients in MHC- and mH-mismatched transplants. Beta2m(-/-) mice accepted MHC class I-expressing BM grafts and developed significant GVHD. MHC (H-2)-mismatched recipients developed acute lethal GVHD. In contrast, animals transplanted across mH barriers developed indolent chronic disease that was eventually fatal. Engrafted splenic T cells in all beta2m(-/-) recipients were predominantly CD3+alphabetaTCR+CD4+ cells (15-20% of all splenocytes). In contrast, CD8+ cells engrafted in very small numbers (1-5%) irrespective of the degree of MHC mismatching. T cells proliferated against recipient strain antigens and recognized recipient strain targets in cytolytic assays. Cytolysis was blocked by anti-MHC class II but not anti-CD8 or anti-MHC class I monoclonal antibodies (MoAbs). Cytolytic CD4+ T cells induced and maintained GVHD in mH-mismatched beta2m(-/-) mice, supporting endogenous mH presentation solely by MHC class II. Conversely, haematopoietic beta2m(-/-) cells were unable to engraft in normal MHC-matched recipients, presumably due to natural killer (NK)-mediated rejection of class I-negative cells. Donor-derived lymphokine-activated killer cells (LAK) were unable to overcome graft rejection (GR) and support engraftment.