Bone marrow necrosis in neuroendocrine tumor of the thymus.

The prognosis of patients with marrow necrosis secondary to neoplastic disease (often gastric adenocarcinoma) was found to be extremely poor with a median overall survival (OS) of few months. This case confirms the very poor prognosis and shows an association with a neural endocrine adenocarcinoma of the thymus.

Bone marrow necrosis is a relatively uncommon clinicopathologic entity. It is most commonly found in patients with neoplastic disorders1, 2 and severe infections3. Physiopathology is unexplained, and prognosis is very poor.

We report the case of a patient diagnosed in 2017 in Hospital Center of Valenciennes.

A 71‐year‐old woman was admitted in emergencies for a change in general state, asthenia, and paleness. Biologically, she presents severe anemia and thrombopenia.

At the entrance, the full blood count revealed a severe nonregenerative anemia (Hb: 3.9 g/dL; reticulocytes: 89 × 109/L) and a severe thrombopenia (platelets: 25 × 109/L) with erythromyelemia and schistocytes. Other biological results showed elevated lactate dehydrogenase, transaminase (hepatic cytolysis), ferritin, an inflammatory syndrome, renal failure and a low prothrombin time.

This clinical presentation suggested four hypotheses: activated macrophagic syndrome, disseminated intravascular coagulation, thrombotic microangiopathy, but, finally, main hypothesis was medullary invasion or medullary infarction.

Thoracic‐abdominal‐pelvic scan was not showing abnormalities.

Sternal and iliac bone marrow aspiration revealed dark smears after May‐Grünwald‐Giemsa (MGG) coloration. Microscopic evaluation showed disintegrated cells and pycnotic nuclei. However, there was any nonhematopoietic cell observed in bone marrow smears (Figure 1).

Figure 1

Microscopics images of medullary necrosis (A, Myelogram is richly cellular. The cells have an indefinite outline, and the intercellular space is purplish in color. May‐Grünwald‐Giemsa (MGG), immersion oil 500x) (B, At high magnification, cells are not identifiable with pycnotic nuclei, and external contours of the cells are not visible. The intercellular space shows a granular aspect, probably due to the degeneration of the stroma. MGG, immersion oil 1000x)

Histological study confirmed probably bone marrow necrosis, and an underlying pathology was found with a neural endocrine poorly differentiated adenocarcinoma of the thymus. PET scan allowed to show a medullary invasion of tumor.

General supportive measures were employed with red cell and platelet transfusion.

Chemotherapy was discuted, but the condition of the patient was too unstable for treatment.

The patient died 2 weeks later.

In the literature, etiology of bone marrow necrosis is reported with hematologic malignancy in 60% of cases and solid tumors in 31% of cases. The most frequent of hematologic malignancy are myeloid or lymphoblastic leukemia, chronic myeloid leukemia, and lymphoma. Concerning solid tumors, the most frequent is gastric adenocarcinoma followed by cancer of unknown origin, prostate adenocarcinoma, stomach, and colon cancer.4 In 9% of cases, there are other etiologies such as severe infections, drugs, sickle cell disease, and antiphospholipid syndrome.5

The symptoms of bone marrow necrosis include bone pain and episodes of fever, which are related to anemia and thrombocytopenia.

The prognosis of patients with marrow necrosis secondary to neoplastic disease (often gastric adenocarcinoma6) was found to be extremely poor with a median overall survival (OS) of few months.7 This case confirms the very poor prognosis and shows an association with a neural endocrine adenocarcinoma of the thymus.

CONFLICT OF INTEREST

None declared.

AUTHORSHIP

BD: involved in interpretation of myelogram, drafting of the manuscript, and final approval of the manuscript. CH: contributed to reinterpretation of myelogram, discussion about the diagnosis, and final approval of the manuscript.