Let It Be

I have a split personality when it comes to paraffin blocks. One part of my being strives to be the ultimate archivist, much like an obsessed philatelist or a fanatical collector of any sort. A significant proportion of each day is spent secondarily coding diagnostic oddities in our computerized database to permit subsequent retrieval. For example, the analysis of cases of edematous lupus erythematosus and dermatomyositis that were assembled and tabulated by my colleague, Dr. Laura Pincus, was only possible because a specific data code indicating ‘‘LE with edema’’ had been tagged to each individual case by my colleagues and me [1]. My instinct as an archivist drives me to safeguard tissue with the hope that the coded seeds will bear fruit in a future study or lecture. To paraphrase Paul McCartney, let it [the tissue] be. If preserving tissue is my Mr. Hyde, then getting additional sections to ferret out an exact diagnosis is my Dr. Jekyll. My mentor, Dr. Wain White, drilled into me the value of additional sections as a young, impressionable resident in anatomic pathology. The White approach serves me well daily. It relies on exacting scrutiny of conventional sections but also on an awareness and imagination that sometimes the key finding is just out of reach of the current plane of section. ‘‘Level sections are your best special stain’’ was Wain’s maxim. (As a brief historical note, Wain conveys that the axiom was coined by a colleague, Dr. Donald McClure, while both were serving as pathologists at St. Joseph Hospital in Denver; in retirement, Dr. McClure is a proprietor in Ayres Vineyard in the northern Willamette Valley.) All of us have been astounded by the miracle of levels. Deeper sections hold the power to unexpectedly divulge Sarcoptes scabiei or to morph leukocytoclastic vasculitis into herpesviral infection. Often deeper sections show nothing, but their occasional cataclysmic benefit can be addictive. Sadly, level sections may also exhaust the tissue block. In a recent editorial, the issue of preservation of tissue was mentioned in passing [2]. A young adult woman with a large cutaneous pigmented lesion underwent a sizable punch biopsy of the area of greatest clinical atypicality, perhaps the darkest area, and a diagnosis of melanoma was issued for the specimen. Based upon the diagnosis of melanoma, the patient underwent wide excision of the remainder, and a biphasic residuum that suggested the possibility of a combined melanocytic nevus was found. The identification of a residuum that was not clearly melanoma created diagnostic ambiguity, and the case was referred in consultation to the University of California, San Francisco. Upon consultative evaluation of the re-excision specimen, it was clear that the exact nature of the residual melanocytic proliferation and the attempted piecing back together of what had been present in the first place would only be possible if the original punch biopsy was obtained for comparison. Retrieval of the original punch eventuated in the receipt of numerous slides demonstrating an intradermal and superficial subcutaneous proliferation of slightly spindled and ovoid melanocytes with finely melanized cytoplasm distributed in nests and fascicles. Occasional melanocytes in mitosis could be found. Some of the received slides consisted of lineage-specific immunostains, which probably were not germane to the final interpretation, as whether the proliferation was melanocytic or not was never seriously in doubt (the issue of resource overutilization in this context has been discussed in a past commentary [3]). A Ki-67 immunostain was certainly relevant and showed a modest elevation in the overall cell proliferation index, but the elevation was insufficient to be decisively diagnostic. Additionally, several sets of level sections, presumably obtained in pursuit of additional meaningful diagnostic attributes such as mitotic figures, were included. Our consultative assessment was that the nature of the proliferation was ambiguous based upon conventional microscopy, and therefore we attempted to complete molecular testing via array-based comparative genomic hybridization (aCGH). Upon recutting of the paraffin block as part of an aCGH preparatory protocol, only a small sliver of tumor remained. Because of the unavailability of tissue, molecular