Dr. Olayemi Sokumbi discusses 3 specific pitfalls in CPC, including challenges and strategies for successful diagnoses.
Olayemi Sokumbi, MD, is Associate Professor in the Department of Dermatology and Department of Laboratory Medicine and Pathology at the Mayo Clinic in Jacksonville, Florida.
“I think we all know as dermatologists, but perhaps it never hurts to reemphasize, that the biopsy is one of the most important tools that we have in our practice of dermatology,” said Olayemi Sokumbi, MD, who presented “Common and Uncommon Pitfalls in Clinical and Pathological Correlation” at ODAC Dermatology Conference 2022.
“Performing a biopsy can be challenging sometimes, particularly depending on the sample needed or the location that we’re interested in sampling. And it’s so important to provide as much clinical information as possible.”
This includes not only getting the appropriate samples, but also providing photos when available, said Dr. Sokumbi.
“[The biopsy] can easily be rendered useless if we’re not using clinical pathologic correlation to ensure we get the most out of the test.”
Dr. Sokumbi discussed three specific pitfalls she calls the double whammy, missing the unknown, and staying superficial.
1. The Double Whammy
The “double whammy” scenario is one in which the clinical and histologic mimic are similar, said Dr. Sokumbi, who shared the case of a patient who had a panniculitic disorder involving the lower extremities.
“The clinical differential diagnosis included lupus profundus, as was appropriate, in addition to a lymphoma that could occur in the subcutaneous tissues. The biopsy was reviewed by an outside dermatopathologist and a diagnosis of lupus profundus was rendered. Unfortunately, the patient progressed and ended up with diagnosis of gamma delta T cell lymphoma when we performed repeat biopsies at Mayo Clinic.”
Situations like this with a clinical differential diagnosis that is similar to a histologic differential diagnosis makes clinical pathologic correlation challenging because the clinical differential diagnosis is identical to the histopathologic differential diagnosis, said Dr. Sokumbi.
“Important things to consider with that pitfall include the importance of repeat biopsies, particularly when you’re dealing with conditions that can mimic one another, and the need to be aware of the histopathologic subtleties that might be important in distinguishing entities that might mimic one another clinically with the same mimic on histopathology.”
2. Missing the Unknown
According to Dr. Sokumbi, “missing the unknown” is commonly a reason for a descriptive diagnosis on histopathology.
“And usually what that means is you look under the microscope, the findings are there, but they’re not specific. And perhaps they’re not specific because we’re not aware of the description of new clinical correlates.”
Dr. Sokumbi shared the case of a patient who presented with symmetric papules involving the elbow. Histopathology showed an infiltrate that could look like polymorphous light eruption [PMLE] but wasn’t, she said.
“It was superficial and deep with lymphocytes and papillary dermal edema. However, when we looked at the patient clinically, the patient did not have PMLE.”
In this case, it was important to be aware of a condition that affects the elbows and occurs in the spring and summer months, said Dr. Sokumbi.
“In this particular scenario, the challenge with clinical pathologic correlation is you will always miss an entity you’re not aware of, so I call that missing the unknown.”
3. Staying Superficial
‘Staying superficial’ is what Dr. Sokumbi calls “a very common and unfortunate scenario.”
“This is where a biopsy sample is not representative of the problem.”
She shared the case of an African American female with unusually configured pigmented patches on the bilateral lower extremities.
“A superficial shave biopsy had been done and she was given a diagnosis of post inflammatory hyperpigmentation.”
After receiving a punch biopsy at the Mayo Clinic, the patient was diagnosed with macular lymphocytic arthritis, said Dr. Sokumbi.
“The original shave biopsy was at the level of the superficial dermis. However, the diagnostic findings were in the deep dermis and subcutis.”
The pitfall, in this case, is staying so superficial that you don’t have the appropriate sample, she said.
“I tell the residents every biopsy has a star. The star of the biopsy was found in the deep dermis and the subcutis and it showed lymphocytic vasculitis. The patient was given a diagnosis of macular lymphocytic arthritis, a diagnosis that really was not challenging to make on histopathology, but it is impossible to render a diagnosis if you do not have the adequate sample.”
Understanding where the pathology lies is key, said Dr. Sokumbi.
“Is it an epidermal process? Is it a dermal process or a subcutaneous process? Understanding that allows one to appropriately sample the process so that one could render a more definitive and accurate diagnosis.”