Histio Makes History

An 81 year old female presented to the head and neck clinic after being diagnosed with cutaneous T cell lymphoma of the posterior mid-parietal scalp at an outside institution. She was initially treated with Brentuximab every three weeks but developed significant toxicities. The patient’s previous “T cell lymphoma” material was reviewed at our institution and the immunophenotypic report described the neoplastic cells as being positive for CD45, CD2, CD4, BCL6+, CD3 (subset), and CD123 (scattered), while negative for CD7, CD8, CD20, CD30, CD56, EBER ISH, PAX5, and lysozyme. Immunohistochemical slides were not provided for review. Flow cytometric analysis determined that there was no immunophenotypic evidence of a clonal T cell population in the patient’s peripheral blood.

A second scalp biopsy was performed at another outside institution, and the findings were similar to the parietal scalp; however, there were atypical pleomorphic cells which displayed irregular contours, hyperchromasia, and multiple nucleoli. The atypical cells were predominantly positive for CD4 and diffuse positivity for CD1a. These same pleomorphic cells were negative for CD3, CD8, CD20, CD30, ALK1, BCL6, CD56, EBER, AE1/AE3, SOX10, Desmin, PAX5, MUM1, CD5, and Cam 5.2.

The smears contained large, highly pleomorphic cells with irregular, elongated, and multilobated nuclei, frequent nuclear grooves and folds, fine chromatin, prominent nucleoli, and variable amounts of pale, eosinophilic cytoplasm, alt.

The outside tissue block on the original scalp biopsy was requested, and our pathology department performed additional immunostains. The neoplastic cells of interest were positive for CD1a, S100, CD68 (a small subset), and negative for lysozyme, CD21, CD30, and CD3. Ki67 proliferation index was interpreted at approximately 60%. An unstained FFPE tissue section was sent to a reference laboratory, and the neoplastic cells were strongly positive for Langerin.

While the Brentuximab treatment initially appeared to have a positive impact on the overall disease burden, the PET CT following 3 cycles showed a mixed response, including resolution of cervical lymphadenopathy and identification of multiple new lung nodules and bulky mediastinal lymphadenopathy. Between that and numerous reported toxicities, the treatment protocol was discontinued. The patient was then referred to radiology for a CT-scan guided right lower lobe lung biopsy measuring 2.2 x 1.3 centimeters with an SUV or 29.6.

In the CT Scan suite, we received multiple FNA passes from the interventional radiologist and made air-dried and alcohol-fixed smears, rinsing the residual needle material into a tube of balanced salt solution for a cell block preparation. We determined our specimen was adequate for scant tumor cells, as depicted on the Diff-Quik smears below.

Images 1-2. Lung, right lower lob, CT-guided FNA. Diff-Quik stained smears.

In comparison to the material from the second scalp biopsy, the cells from the lung biopsy appeared identical. Our Pap-stained smears and H&E cell block sections also demonstrated the highly pleomorphic cells described above.

Images 3-6. Lung, Right Lower Lobe, CT-guided FNA. 3-4: Pap-stained smears, 5-6: H&E sections (5: 100x, 6: 400x).

Immunostains performed on the cell block slides with adequate controls show that the tumor cells are positive for CD1a, CD4, partially positive for CD45 and S100, negative for AE1/3, TTF-1, and p40.

Images 7-8. Lung, Right Lower Lobe, CT-guided FNA. Cell block section immunohistochemistry. 7: CD1a-positive; 8: partially S-100-positive.

Our pathologists felt the cells from the second scalp biopsy and the lung biopsy were representative of a Langerhans cell sarcoma, a form of malignant histiocytosis, rather than a T-cell lymphoma. It is possible that the first scalp biopsy’s diagnosis of T-cell lymphoma was due to sampling error and the pleomorphic cells of interest were missed. The Ki-67 proliferative index of 60% helped to distinguish between Langerhans cell histiocytosis and Langerhans cell sarcoma.

Molecular testing performed on the core biopsy was negative for a BRAF mutation and positive for an NF1 inactivating mutation. The tumor may then be sensitive to mTOR inhibitors and MAPK pathway inhibitors, such as MEK inhibitors. Appeals for a MEK inhibitor were denied by insurance, but fortunately, the tumor also demonstrated high PD-L1 expression at 90%, making this specific patient a candidate for pembrolizumab, which was fully covered by insurance.

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I can’t help but think about the disparities associated with cancer and the inaccessibility of potentially lifesaving or life-prolonging treatments. Sure, there may be viable alternatives, such as this case, but what if we had equal access to cutting edge, personalized therapies? What if the only therapy available was too costly to bear? Just because a cancer might be rare, such as Langerhans cell sarcoma, it doesn’t mean access to a proven effective therapy should also be rare. Even with drug assistance programs, so many patients face the harsh reality of tapping into their life savings to just to save their own life. When we became medical laboratory professionals, we promised to provide timely and accurate for all of our patients. Now, it’s time that pharmaceutical companies and our healthcare system as a whole work together to provide high quality, low-cost, readily accessible and personalized treatment options to every patient. They deserve that chance to overcome or at least manage their cancer.

-Taryn Waraksa-Deutsch, MS, SCT(ASCP)CM, CT(IAC), has worked as a cytotechnologist at Fox Chase Cancer Center, in Philadelphia, Pennsylvania, since earning her master’s degree from Thomas Jefferson University in 2014. She is an ASCP board-certified Specialist in Cytotechnology with an additional certification by the International Academy of Cytology (IAC). She is also a 2020 ASCP 40 Under Forty Honoree.

Tumor on the Brain

Back in my Master’s program at Jefferson, I fondly remember the week we covered central nervous system (CNS) tumors. I was fascinated by the mnemonic tools we would use to identify different CNS tumors, such as “fried eggs” for oligodendrogliomas, perivascular pseudorosettes in ependymomas, and the whorling associated with meningiomas. Fortunately, for our patients, and unfortunately, for our diagnostic curiosity, we rarely see CNS tumors at my institution. Brain lesions resulting from metastatic carcinomas are typically well-identified via imaging and treated appropriately by the surgical, medical, and radiation oncology teams, but cytologists are available to screen cerebrospinal fluids (CSFs) for CNS involvement. For primary CNS tumors, however, we’re left recollecting the core memory of the second semester of our didactic phase. When a metastatic CNS tumor made its way into our lab, our cytology team swooned with excitement. (Yes, I know, but please introduce me to a lab professional who doesn’t embrace their quirks.) A 27-year-old male patient presented to radiation oncology three years after surgical debulking of a brain tumor at an outside institution. The patient, who was referred to radiation oncology at to treat the residual tumor at the original institution, did not follow up and developed an 8 centimeter recurrence a year after the initial resection. At this point, the patient experienced complete vision loss and underwent a biparietal-occipital craniectomy. A repeat brain MRI was performed a year later, and once again, a large enhancing extra-axial mass was identified along with multiple smaller masses also increasing in size. The patient received radiation after worsening difficulty with ambulation. After almost completing the planned fractions of radiation, the patient elected to stop their radiation therapy due to worsening seizures. A left neck mass was identified six months prior, and while the mass had not grown or caused pain, the patient was referred to head and neck surgical oncology for evaluation. Surveillance imaging demonstrated an enlarged left level 5A lymph node, suggestive of metastatic disease. Multiple ultrasound-guided fine needle aspiration biopsies were obtained from the lymph node, and ROSE was performed. The Diff-Quik-stained and concurrent Pap-stained smears demonstrated lesional tissue, although everything from epithelioid histiocytes to spindle cell melanoma to a renal primary were considered as a differential. Based on the location, a salivary gland primary was also a possibility for this case. The streaked cytoplasm and pseudoinclusions in both smears were concerning for a metastasis of the patient’s primary CNS tumor, but we were still hesitating to make the call.

Images 1-4. Lymph Node, Neck, Left, Level 5A, US-guided FNA. 1-2: Diff-Quik-stained smears, 3-4: Pap-stained smears.

The following morning, the H&E-stained FFPE cell block sections demonstrated the characteristic whorls expected for the patient’s primary, although the idea of metastasis was uncanny.

Images 5-6. Lymph Node, Neck, Left, Level 5A, US-guided FNA. H&E sections (6: 100x, 7: 400x).

We then used immunohistochemical studies to confirm our morphologic diagnosis. Immunostains performed on the cell block slides with adequate controls show that the tumor cells are positive for vimentin and PR (focal), while negative for AE1/AE3, EMA, CK7, CK20, TTF-1, Napsin A, p40, Pax8, synaptophysin, and S-100. The Ki-67 proliferation index fell at 18%, which is consistent with intermediate aggressive disease in a WHO Grade 2 atypical meningioma.

Images 7-8. Lymph Node, Neck, Left, Level 5A, US-guided FNA. Cell block section immunohistochemistry. 7: Vimentin-positive; 8: focally PR-positive.

The patient had next gen sequencing performed on his tissue, which demonstrated an NF-2 mutation, indicating he may benefit from MTOR inhibitors, but he elected not to pursue systemic therapy.

Where meningiomas account for 36% of primary brain tumors, atypical meningiomas comprise only 5-15% of all meningiomas (Cai et al., 202. Extracranial metastasis of atypical meningioma is a rare event, with only a few cases documented in the literature. While meningioma metastases are uncommon, a thorough collaboration between clinical impression and pathologic interpretation is necessary to ensure the possibility is not entirely excluded.

References

Cai C., Kresak J.L., Yachnis A.T. (2021) Atypical meningioma. Pathology Outlines. Retrieved October 11th, 2022, from https://www.pathologyoutlines.com/topic/cnstumoratypicalmeningioma.html.

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-Taryn Waraksa-Deutsch, MS, SCT(ASCP)CM, CT(IAC), has worked as a cytotechnologist at Fox Chase Cancer Center, in Philadelphia, Pennsylvania, since earning her master’s degree from Thomas Jefferson University in 2014. She is an ASCP board-certified Specialist in Cytotechnology with an additional certification by the International Academy of Cytology (IAC). She is also a 2020 ASCP 40 Under Forty Honoree.

Triaging Times

As a clinical instructor and lead cytologist at my institution, I like to remind our newer cytologists and cytology students of the importance of being prepared for FNA biopsies so they develop good habits or best practices as they become more experienced. This level of preparation helps to create a culture of ongoing learning and improvement, which is necessary for the laboratory. In my experience, I’ve met some cytologists who prefer to go into a case blind, with the mindset that knowing the patient’s clinical history in advance muddies their knowledge, skills, and abilities, limiting their mindset by excluding the possibility of other diagnoses. While diving into the unknown might seem exciting, it is also a hindrance and could result in errors, especially when the clinical history helps us triage the patient’s sample. For example, knowing that the patient has a history of lymphoma or that the presentation state includes bulky lymphadenopathy prompts us to collect additional needle passes to send for flow cytometry analysis. Another concern is not knowing whether the patient has a history of breast, gastric, or esophageal cancer, and consequently processing the specimen routinely, which may result in an extended cold ischemic time. This delay in fixation along with insufficient formalin fixation can yield false negatives on ER/PR IHC in breast cancers and HER2 FISH in breast, gastric, and esophageal cancers, which could restrict the use of hormone therapies, such as tamoxifen and aromatase inhibitors for hormone receptor-positive (HR+) cancers, or trastuzumab for HER2+ cancers. I cannot overemphasize the importance of familiarizing yourself with clinical history and communicating case specifics while you act as a mediator between clinician and pathologist.

Whether the clinical history impacts the pre-analytical phase, such as specimen collection (limiting cold ischemic time or collecting additional needle passes for ancillary studies) or the analytical phase, as such processing (formalin fixation) and diagnosis (selecting an appropriate immunoprofile), we must remain vigilant and proactive in laboratory medicine. In this case, knowing the patient’s clinical history was of the utmost significance as it helped to reduce the number of immunostains and ancillary studies necessary to make the diagnosis. Using morphologic criteria in tandem with the patient’s clinical history narrowed the differential diagnoses to just two possible types of cancer, presented below.

A 59 year old male patient presented to the emergency room after an automobile accident. On imaging, the X-ray and CT scan identified a left humerus mass and fracture, and bloodwork was performed. His medical record was sparse and uneventful with no recent visits or encounters. To build a more comprehensive wellness profile and prepare for surgery, he was also offered a one-time screening for Hepatitis C, as an adult who was born between 1945 and 1965.

The left humerus mass was biopsied via CT-scan guidance and two passes were obtained. The Diff-Quik stained smears demonstrate large polygonal cells, some with abundant, granular cytoplasm and some isolated cells with naked nuclei. Vessels also appear to traverse some of the cell groups.

Images 1-2: Bone, Humerus, Left, CT-guided FNA. Diff-Quik-stained smears.

The Pap-stained smears also demonstrate polygonal cells with granular cytoplasm, nuclei with coarse chromatin, and prominent nucleoli. An interesting feature frequently identified in this case is the intranuclear inclusions, and in hindsight, a focus on these may have further reduced the number of immunostains performed.

Images 3-5: Bone, Humerus, Left, CT-guided FNA. Pap-stained smears.

The H&E-stained cell block sections show trabeculae with endothelial wrapping around the cell cords. While renal cell carcinoma was listed as a differential diagnosis due to its telltale oncocytic cytoplasm and vascularity, hepatocellular carcinoma was favored.

Images 6-7: Bone, Humerus, Left, CT-guided FNA. H&E sections (6: 100x, 7: 400x).

Immunostains were performed using proper positive and negative controls on the cell block sections, and the tumor cells show positive staining for Arginase, cam5.2, and Hepar1, while negative staining for CK7 and PAX8 (not shown).

Images 8-10: Bone, Humerus, Left, CT-guided FNA. Cell block section immunohistochemistry. 8: Arginase-positive; 9: cam5.2-positive; 10: Hepar1-positive.

Fortunately, before ordering immunostains, both our cytologist and pathologist working on the case peered into the patient’s medical record and noticed that he had recent bloodwork which demonstrated a positive Hepatitis C screening. This diagnosis was as recent as the identification of his humerus mass. Had it not been for his car accident, I can’t imagine how long he would have gone undiagnosed for both hepatitis and metastatic hepatocellular carcinoma. Incidental findings save lives, folks.

Granted, in settings of unknown primaries with widespread metastatic disease, such as carcinomatosis, an extensive workup is almost always inevitable. Narrowing down possible etiology based on information such as gender, age, and environmental or occupational exposure can help, but that doesn’t always yield a definitive answer as time- or cost-effectively as possible. In this case, that one clue of untreated Hepatitis C was all the cytopathology team needed. A rarity, sure, but as we are asked to do more personalized tests with less material, think of the patient’s specimen as a puzzle and keep your eye out for a clue both under the microscope and behind the computer. You never know what you might find that reduces errors and unnecessary testing while efficiently leading to a definitive diagnosis.

-Taryn Waraksa-Deutsch, MS, SCT(ASCP)CM, CT(IAC), has worked as a cytotechnologist at Fox Chase Cancer Center, in Philadelphia, Pennsylvania, since earning her master’s degree from Thomas Jefferson University in 2014. She is an ASCP board-certified Specialist in Cytotechnology with an additional certification by the International Academy of Cytology (IAC). She is also a 2020 ASCP 40 Under Forty Honoree.

Cytology Case Study: Strike a Chord

Every FNA ROSE attended where the patient is conscious and attentive can be tricky to navigate. You have to remain cognizant of your word choice, your demeanor, and the delivery of your adequacy statement to the clinician. The patient is already in a heightened state of awareness because he or she is about to be probed with a needle (or six!) for a test that is likely to rule out a benign or malignant process. I prefer to go into my biopsies with some sort of clinical picture and as many details as I can retain – is there a previous history of cancer? Where is the lesion located? Is it a single mass or are there multiple lesions? What does the radiologic imaging suggest? Are there any elevated serum tumor markers? I need to be able to walk the walk and talk the talk. However, there are rare instances when cytotechs are asked to rush down to an unscheduled add-on biopsy where we have yet to research the impression documented in the patient’s medical record. In those situations, I ask the clinician (typically an interventional radiologist) all the questions I can think of while still emulating some form of confidence to the patient.

I entered the procedure room and greeted the radiologist, radiology fellow, tech, nurse, and the patient, a 57-year-old male who was prone and alert on the table. I jotted down notes during the timeout and pulled the radiologist aside to ask, “does the patient have a history of cancer?” In this case, the answer was “they have a soft tissue tumor in the left gluteus, which is what we’re biopsying.” “Alright, let’s get those differentials rolling – sarcoma; after my hibernoma experience – a lipomatous tumor; or could it be a carcinoma (because yes, I’ve seen a lung adenocarcinoma metastasize to the gluteal muscle before)? Hmm… what else? What other mesenchymal tumors could originate here… or metastasize here?” My brainstorming balloon was popped by the radiologist asking if I was ready for the first needle pass. I replied, “Yes, of course!” I glance over at the patient and smile, trying to assure him AND myself that I’ll be able to give him a definitive answer to his puzzle.

Here’s what I visualized under the microscope after I stained the first air-dried smear in our Diff-Quik solutions.

Images 1-2. Left gluteal FNA, DQ-stained smears.

My inner monologue became: “Well, it’s not a sarcoma or a carcinoma. It doesn’t look malignant.  Not quite a hibernoma. What is with that myxoid matrix? It’s not mucinous or serous, so… what is it…? It’s granular! Wait. Those nuclei. They’re so… what’s the word? It’s definitely representative of the lesion. Regardless, it’s adequate!” I turned away from my microscope to face the team – “The sample is adequate. May I have a few more passes for my cell block, and will you collect core biopsies, too? “Yes and yes,” the radiologist replied. I smiled again at the patient, and he mouthed, “thank you.” “Phew, mission accomplished,” I thought. “Now what the heck are those hallmark cells called mixed in with a majority of epithelioid cells arranged in chords?”

I climb the stairs up to the lab and do a quick Google search. “DUH! Physaliphorous cells!” These cells have a distinct feature where the nucleus is centrally located but is also scalloped by cytoplasmic vacuoles. There weren’t as many physaliphorous (physaliferous) cells as I had hoped to appreciate. Some of the cells looked lipoblastic in nature with larger vacuoles displacing the nuclei to the periphery, almost signet ring in nature, many were cuboidal. But that was it… those cells! Now, imagine the scene in Finding Nemo where Nemo struggles to tell his classmates he lives in an anemone. That was my garbled attempt at pronouncing “physaliphorous” to the attending pathologist when sharing my interpretation. She looked at me like I was saying anything other than the word I was trying to reproduce. I cannot blame her; I still turn beet-red at the memory. But I was convinced that a chordoma was the tumor I presented to her.

After I processed my FNA, I examined the patient’s electronic health record to see if he had any previously biopsied neoplasms on file, and much to my surprise, the patient was diagnosed with a primary chordoma of the sacrum and treated with en bloc resection and radiation in 2013. Mutation analysis was performed on the resection of this chordoma, which exhibited a homozygous loss of CDK2NA (p16). The patient had one recurrence at an outside facility in 2015 and transferred his care to our institution for follow-up. Now, the patient presented with this gluteal metastasis and soon thereafter, a paraspinal metastasis. As the patient’s chordoma did not completely respond to radiation, the clinical care team turned to the tyrosine kinase inhibitor, Gleevec, which was discontinued due to disease progression. The patient’s regimen then went on to include sunitinib, which was also discontinued due to disease progression, palbociclib, then nivolumab, followed by radiation to the thoracic spine, sorafenib, and now is on a clinical trial for patients with advanced refractory cancers.

When I turned in my Diff-Quik & Pap-stained slides and the cell block H&E sections with a diagnosis of chordoma the next day, the attending cytopathologist paged through one of our cytology texts to a tidbit on chordomas before signing out the case. She reviewed the section with me. Other than the unique physaliphorous cells, it turns out a diagnosis of chordoma is fairly rare, as it is the only malignancy derived from the notochord, typically occurring at either end of the axial skeleton.1 Metastasis of these tumors is also rare, so this case of widespread metastatic disease was even more intriguing to me.

Images 3-8. Left gluteal FNA . Images 3-5, Pap-stained smears; 6-8, H&E cell block sections.

References

  1. Cibas, E. S., & Ducatman, B. S. (2009). Cytology: Diagnostic Principles and Clinical Correlates, Expert Consult – Online and Print (3rd ed.). Saunders.

-Taryn Waraksa, MS, SCT(ASCP)CM, CT(IAC), has worked as a cytotechnologist at Fox Chase Cancer Center, in Philadelphia, Pennsylvania, since earning her master’s degree from Thomas Jefferson University in 2014. She is an ASCP board-certified Specialist in Cytotechnology with an additional certification by the International Academy of Cytology (IAC). She is also a 2020 ASCP 40 Under Forty Honoree.