Mastering the Skin Biopsy: Dermpath Insights, CTCL & Tricky Diagnoses with Dr John Griffin

A biopsy is only as useful as the tissue you send, and information that travels with it. In this episode of The Spot Check, Jamie Restivo, PA-C, is joined by dermatologist and dermatopathologist John Griffin, MD, for a practical look at what happens between the clinic and the microscope, and how more thoughtful biopsy technique can lead to clearer answers when the diagnosis is anything but straightforward.

Dr. Griffin starts with a deceptively simple question: where is the pathology? Thinking about whether a process lives in the epidermis, dermis, or deeper in the fat can change the type and depth of biopsy needed before the blade ever touches the skin. From autoimmune blistering disease and connective tissue disorders to vasculitis and alopecia, they work through the details that matter, including lesion age, biopsy depth, specimen selection, and occasions when one sample may tell a very different story.

They also take on some of the diagnoses that can be particularly difficult to capture. For suspected cutaneous T-cell lymphoma, Dr Griffin explains why multiple biopsies may be more important than choosing between a broad shave and punch alone, recent topical steroid use that can obscure the lymphocytes needed for diagnosis, and the reasons a more raised or indurated lesion may offer a better target. The conversation also moves through pigmented lesions and recurrent pigment within a scar, where knowing the history of a prior biopsy can materially change how the dermatopathologist interprets what is under the microscope.

But the larger lesson goes beyond biopsy technique. Dr. Griffin asks clinicians to think of the pathology requisition as a consultation, not a one-way lab order. A photograph, a precise description, a meaningful differential, or a phone call when the report does not fit the patient can all add context that histology alone cannot provide. As he puts it, the clinician sees patterns on the patient, and the pathologist sees patterns under the microscope. Getting to the right diagnosis often depends on making sure those two pictures line up.