Christopher VandenBussche, MD, PhD


The Interesting Case Conference (ICC) has been a long-standing educational conference within the Cytopathology Division at the Johns Hopkins University School of Medicine. The ICC has existed for at least 25 years, and is believed to have originated in some format during the time of our laboratory’s founder, Dr. John Frost, and subsequently evolved into its modern, weekly format under the directorship of Dr. Yener Erozan.

Each week, one trainee (resident or fellow) is responsible for preparing cases for the subsequent week’s ICC conference. Typically, five cases are prepared; cases are encouraged to have histologic follow up and at least one of the cases should be an exfoliative cytology specimen such as a Pap test specimen. The trainee responsible for organizing the conference must obtain all relevant glass slides from the cytopathology and surgical pathology archives, as well as being familiar with any relevant clinicoradiologic information, items on the differential diagnosis, and pertinent ancillary tests (whether or not actually performed). The slides with the best material are marked so that suboptimal slides are not presented. All other participants, including the “hot seat” faculty member presenting the weekly conference, are completely blinded to the cases being presented.

To reduce preparation time, interesting cases are often derived from recent cases either saved by fellows from earlier in the year or from residents in the week before the ICC is presented. During routine sign-out, any cases potentially useful as ICC cases are flagged and logged by office staff, such that the trainee responsible for the conference can easily find them later. Over time, a sense of pride regarding the presentation of ICC cases has developed, with some trainees seeking out the most challenging cases, or a group of cases that fit a certain theme, such as lesions with spindle cell morphology. Challenging cases are encouraged, as the primary goal of the ICC is to stimulate discussion and formulate non-specific diagnoses rather than to arrive at the correct answer.

The ICC takes place in the cytopathology sign-out room and is open to all residents and cytotechnologists. However, attendance is required of the 4-6 residents and trainees on service in a given month, as well as all available cytopathology faculty. The trainees sit at the multi-headed scope along with the “hot seat” faculty member, whereas others attending the conference view slides from a mounted television screen. The “hot seat” attending is given the slides to the first case with minimal information (e.g., “A 63 year old male with a mediastinal mass”) and selects one of the trainees (now the “hot seat” trainee) to work through the case. The trainee responsible for preparing the conference cannot be chosen as a “hot seat” trainee.

When possible, the case material is presented as it would be reviewed in real life, only moving to additional slides once discussion resulting from a slide has been exhausted. In the case of a fine needle aspiration specimen, a Diff-Quik stained slide would be presented first, followed by a Pap-stained slide, followed by cell block material.

The hot seat trainee is expected to lead the discussion as the slides are being driven; expectations differ based on the trainee’s experience and thus younger trainees may receive more prompting than more experienced trainees. The discussion often starts with a description of the cytomorphologic features – beginning with the adequacy and cellularity of the case, the presence or absence of tissue fragments or cellular clusters, the presence of architecture and background material, and ending with nuclear and cytoplasmic features. Once the cytomorphology has been adequately discussed, the hot seat attending will prompt a discussion of the differential diagnosis – the hot seat trainee must decide if the specimen is lesional, neoplastic, benign or malignant, and attempt to classify malignant lesions into a general category (such as carcinoma, melanoma, sarcoma, or lymphoma). The hot seat trainee is often encouraged to provide an actual diagnosis (such as “malignant epithelioid neoplasm”) as well as an academic “guess” at a specific entity (such as “metastatic lobular breast carcinoma”).

During the presentation, the hot seat attending may ask for more information to be revealed about the case to help stimulate further discussion. For instance, more information may be asked about the radiologic findings or patient history, and these answers may be provided if they do not reveal the diagnosis. Once the hot seat attending and trainee have exhausted their discussion (and prior to discussion of ancillary studies), discussion is opened to other attendees’ additional suggestions or important points not previously discussed. This brief discussion among attendees usually results in one or two additional possible diagnoses.

At this point, the hot seat trainee discusses any ancillary tests that should be performed if sufficient material were available. The selection of ancillary tests is meant to be a focused discussion geared towards confirming or eliminating the most favored diagnoses. For instance, a panel of three immunostains may be requested, or an ancillary test to detect a fusion gene. While flow cytometry and microbiologic studies are often discussed, they are usually discussed during the presentation of the Diff-Quik stain, which is when a dedicated specimen would have been taken during rapid on-site evaluation.

The trainee responsible for organizing the conference can provide known or inferred test results, which may lead to the confirmation of a specific diagnosis. Once any further discussion has been exhausted, the patient’s full case history and diagnosis is revealed, and any subsequent histologic specimens can be shown. The diagnosis made on the cytology specimen is also revealed, along with any caveats (e.g. diagnoses of a recurrence are more easily made when the patient’s history is known). Some particularly exceptional trainees organizing the conference will also provide a brief, well-researched discussion of the particular entity to supplement previous discussion. A different hot seat trainee is then selected to present the next case with the hot seat attending; cases are presented until no more remain or the hour assigned to ICC has expired.

The ICC can be daunting to both trainees and attendings, as they must present unknown cases to a room full of their peers. However, the ICC is well liked among residents, as revealed in their end of rotation feedback. The ICC provides a dedicated time for cytopathology and pathology to be discussed among those with diverse experiences. Senior residents and fellows may discuss cutting-edge topics (such as a new immunostain or molecular test) learned on recent subspecialty rotations. Long-standing misconceptions in practice may be corrected. The ICC also serves as an additional method for correlation between cytology and histology; a case flagged for ICC will eventually be shown once a surgical specimen is available, to the benefit of all attendees. As the ICC preceded most of the modern day quality improvement measures, it has served as one of our earliest quality assurance conferences, with all presented cases documented since 1998. Remarkably, this format has changed very little over time.

Christopher VandenBussche, MD, PhD
Cytopathology Fellowship Program Director
Johns Hopkins Hospital