I (EBS) first became aware of this fixative in a GI biopsy course offered sometime between 1973-75 by John Yardley, M. D.; photos of intestinal biopsies looked amazingly better than with 10% NBF (the routine fixative until sometime in the 1980s). Some of us in our group have used Hartmann's fixative patially in our practice since about 1976. But, beginning about 2007, we have had to be sure that we had some diagnostic tumor tissue also fresh into 10% NBF (without microwave co-fixation) which is the standard fixative technique for IHC & molecular testing.

• It is cheaper than 10% NBF.
• It penetrates pretty rapidly.
• Hartmann's is a "softer" fixative than the mercuric fixatives, 10% NBF, or even the zinc-formalin such as "GI-fix"...microtomy-favorable.
• It causes much less tissue shrinkage than 10% NBF or the mercuric fixatives (such as B5)...except breast cancer where-in it sometimes causes cancer clusters to separate from stroma & mimic "invasive micropapillary breast cancer". Therefore, it is superior in correctly reflecting the histological expression of tumor patterns such as nodularity in a lymphoma and the various stromal patterns in soft-tissue and mucinous lesions. It fixes nuclei in a way that more readily corresponds with cytological features of nuclei...great for discerning mitoses (MAI).
• Best of all, it causes DNA-rich (nucleus-dense) tissue (cancer & lymph nodes) to differentially turn white and do so rapidly. But, this differential fades after about 48-72 hours in a Hartmann's bath. This white color is the key to the subgrossing advantage. Example: 95 gram, 7cm polypoid villous adenoma coarsely section and into Hartmann's and all epithelium tunrs white so that one can everywhere localize the villous mucosal component, see its interface with the scant submucosa & note any non-smooth interfaces to select as blocks so as to confidently r/o any invasion (most of the villous component is discarded from study...[L09-9782]).
• Hartmann's lakes RBCs.
• Molecular tests: since it is not a heavy-metal fixative, it likely works OK with DNA-based molecular studies such as for KRAS gene mutations (we've not confirmed). And, I have no idea as to effect on RNA.

So, colonic & other intestinal polyps or malignancies fixed in Hartmann's can be visually (grossly...this is a sub-grossing technique) discerned as to (1) depth of penetration (especially relative to the submucosa & muscularis propria) and a "deepest-penetrated" block selected with great confidence & properly placed corect-side-down in the cassette; and, (2) finding any aspect of tumor which has involved or penetrated serosa. Even sub-millimeter deposits of cancer stand out white against any tan grey fibromuscular soft tissue; the blocks are selected with great confidence & properly placed corect-side-down in the cassette.

Breast cancers, after taking a portion into 10% NBF for marker studies, lumpectomies & mastectomies can be sliced after Hartmann's fixation and the sharply white cancer coloration contrasting against a yellow or light tan grey stromal background of benign parenchyma allows confident interpretation of margin status with the naked eye & block selection & tissue slice orientation in the cassette to confirm the margin status histologically. The differentiating whiteness of the cancer depends on cellularity (so, lobular is more problematic). This color differential helps one see thin cancer connections between epicenters or bloomletts within one mutinodular cancer vs. situation of several closely adjacent cancers. Similarly, it is a real help in finding multifocal cancer in mastectomy cases, too. Grading: one can discern the mitotic & nuclear-features portions of grading & MAI & mitotic rate counting better with this fixative.

In lung resections (pneumonectomy, lobe, or wedges), this fixative is ideal for (1) finding intrapulmonary metastases when infused down airways or injected by needle into parenchyma. Small bronchi richly surrounded by chronic inflammatory cells may be white on cross-section. And, (2) it may help you to serially slice an area of possible pleural involvement in order to find any "white" penetration and position the slice correct-side-down in the cassette so as to histologically demonstrate the pleural invasion.

For decades, we have confirmed Hartmann's value in lymph node dissections² in that we can routinely find even 1-3 mm nodes (because nodes become (1) palpably distinct from fat and (2) turn white...as seen on cross-section).

For soft tissue masses likely to be sarcomatous, Hartmann's is great for (1) optimally portraying the malignant histological pattern AND (2) helping to sub-gross as to margins.

The old-time, near-sighted cartoon character, Mr. Magoo, who is seen having misplaced his glasses, reminds me of how I'd (EBS) feel if required to do without the subgrossing, "revealing" advantages of this fixative. And I personally feel that careful stage & margin assessment with this differential color visualization is far less subject to artifacts potentially leading to mis-assessment histologically.

HISTORY:

Dr. Hartmann gives credit to Dr. Yardley (at Johns Hopkins) for instituting this fixative at that institution (sometime between 1962 and 1968); he indicates that his reagent mixing ratios were a little different from our formula¹.  He believes that it was developed by Dr. Davison.  It is somewhat similar to "Tellyesniczky's acetic alcohol formalin".  A formulation similar to this (but including some diethyl ether) was reported relative to axillary lymph node dissections for breast cancer.

Formula:

1. 10% neutral buffered formalin   900 ml
2. 95% ethyl alcohol                    1200 ml
3. glacial acetic acid                      400 ml
4. water                                       1200 ml

1. Hartmann WH, letter to Dr. Shaw concerning this fixative, 15 Oct. 1991.
2. Loren R, et. al., "Lymph node revealing solution: A new method for detection of minute axillary lymph nodes in breast cancer specimens." Am J Surg Pathol. 1997; 21(11):1387-1390.