Q & A

November 2004

Richard A. Savage, MD, Editor

Q.  Should the general surgical pathologist who infrequently sees testicular biopsies for infertility be signing them out? What are the essential elements of a clinically useful report?

A.  The general surgical pathologist should be able to evaluate testicular biopsies for infertility and provide accurate diagnostic and prognostic information. The interpretation of findings requires clinical correlation, and the urologist should be instructed to provide history and laboratory data regarding sperm count, such as oligospermia or azoospermia, if the descriptive morphologic interpretation is to be clinically relevant. Biopsies should be fixed in Bouin solution or another suitable nuclear fixative—improper fixation may render them uninterpretable. Using special stains, such as trichrome or PAS, is optional.

The surgical pathology report should include a microscopic description and comment section for correlating histopathologic findings with clinical data and suggesting possible etiologies. For example, a normal biopsy from an azoospermic patient is indicative of excurrent duct obstruction. Unless specifically requested by the urologist, it is not necessary to perform cross-section tubule counts of spermatids, which correlate with seminal fluid sperm counts, nor is it necessary to determine the ratio of germ cells to Sertoli cells (normal ratio in young adults, 13:1).

In the majority of cases, a reasonable interpretation can be achieved by noting the characteristics of the following elements:

• Germinal epithelium, including maturation to spermatids/spermatozoa (normal, decreased, or absent). All sampled tubules should also be screened for possible intratubular germ cell neoplasia, unclassified.
• Tunica propria of seminiferous tubules (normal or thickened).
• Leydig cells (normal, relative increase, or hyperplastic).

The size of tubules and alterations in blood vessels or connective tissue can also provide diagnostic clues in some cases.

Using this systematic approach, the pathologist can develop and apply an algorithm for preliminary interpretation. In the majority of cases, this will allow the pathologist to recognize specific morphologic patterns of injury, which can be categorized into testicular causes of infertility—hypospermatogenesis, maturation arrest, germ cell aplasia, Klinefelter syndrome, cryptorchidism, injury by physical or chemical agents, infection, or focal sclerosis. Pathologists should use standard textbooks to become familiar with the spectrum of his to pathologic changes, which may or may not have a specific primary etiology.

Member, CAP Surgical Pathology Committee

Q.  Body fluids and cell counts are always a problem. We now lump macrophage and mesothelial cells together. Is that a common and accurate practice?

A.  There is considerable variation in the way cells in body fluids are counted in the differential. Most experts agree, and the CAP recommends, that these differentials should be done on stained cytospin preparations and not in the hemocytometer chamber. There is also general agreement that non-erythroid cells should be enumerated, including neutrophils, lymphocytes, monocytes, eosinophils, basophils, and more immature white blood cell categories, if present. However, this is where general agreement ends.

Some experts recommend that other cells, such as mesothelial cells, histiocytes, synoviocytes, and malignant cells, be enumerated separately or estimated as a percentage, either individually or under the broad category of “other.” Other experts suggest that they be quantitated separately as 1+, 2+, or 3+. Many agree with your contention that it is often difficult to morphologically separate macrophages and mesothelial cells and, therefore, count them together as a group, either as part of the differential or separately from the differential.

What does this imply? If you do not include these other cells in the differential, you may get a false impression of the relative number of cells present. For example, if a patient has 100 mesothelial/ macrophage/monocytes for every 80 neutrophils and 20 lymphocytes and the total count is low, and if the "other" cells are not included in the differential, then the report will read 80 percent neutrophils and 20 percent lymphocytes, giving a false impression of an acute cellular reaction. Therefore, I favor including these cells in the differential count, which will include neutrophils, lymphocytes, and "other mononuclear cells." Clumps of cells obviously need to be excluded, and it is critical to note separately but clearly that malignant cells are present.

Bibiliography

Henry JB. Clinical Diagnosis and Management by Laboratory Methods. 20th ed. Philadelphia, Pa.: WB Saunders; 2001: 403-424.

Kjeldsberg CR, Knight JA. Body Fluids. Laboratory Examination of Cerebrospinal, Seminal, Serous, and Synovial Fluids. 3rd ed. Chicago, Ill.: ASCP Press; 1993.

Katherine Galagan, MD
Chief of Pathology and Director of Laboratories
Virginia Mason Medical Center Seattle

Advisor, CAP Hematology/Clinical Microscopy Resource Committee